US8987850B2 - Magnetic memory devices having a uniform perpendicular nonmagnetic rich antisotropy enhanced pattern - Google Patents

Abstract

Provided are magnetic memory devices, electronic systems and memory cards including the same, methods of manufacturing the same, and methods of controlling a magnetization direction of a magnetic pattern. In a magnetic memory device, atomic-magnetic moments non-parallel to one surface of a free pattern increase in the free pattern. Therefore, critical current density of the magnetic memory device may be reduced, such that power consumption of the magnetic memory device is reduced or minimized and/or the magnetic memory device is improved or optimized for a higher degree of integration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application is a divisional of U.S. application Ser. No. 13/181,957 filed on Jul. 13, 2011, which claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2010-0072051, filed on Jul. 26, 2010, the entire contents of each of which are hereby incorporated by reference.

BACKGROUND

Inventive concepts disclosed herein relate to a semiconductor memory device, for example, to magnetic memory devices, electronic systems and memory cards including the same, methods of manufacturing the same, and methods of controlling a magnetization direction of a magnetic pattern.

As faster and lower power consuming electronic devices are desired, semiconductor memory devices used therein also need to have a faster read/write operation and/or a lower operating voltage. As one plan to satisfy one or more of the above requirements, a magnetic memory device has been proposed as a semiconductor memory. Since the magnetic memory device operates at higher speed and has a nonvolatile characteristic, it has drawn attention as a next generation memory device.

A magnetic memory device may include a magnetic tunnel junction (MTJ). A MTJ may include two magnetic materials and a tunnel barrier layer disposed therebetween. Depending on the magnetization directions of the two magnetic materials, a resistance value of the MTJ may vary. For example, when the magnetization directions of the two magnetic materials are anti-parallel to each other, the MTJ may have a relatively large resistance value and when the magnetization directions of the two magnetic materials are parallel to each other, the MTJ may have a relatively small resistance value. By using a difference between the resistance values, the magnetic memory device may be used to write/read data.

SUMMARY

Example embodiments of inventive concepts may provide a magnetic memory device reducing power consumption.

Example embodiments of inventive concepts may also provide a magnetic memory device having improved reliability.

Example embodiments of inventive concepts may also provide a magnetic memory device with increased degree of integration

In example embodiments of inventive concepts, a magnetic memory device may include: a uniform free pattern on a substrate and having a first surface and a second surface opposite to each other; a reference pattern on the substrate; a tunnel barrier pattern between the first surface of the uniform free pattern and the reference pattern; and a nonmagnetic metal-oxide pattern contacting the second surface of the uniform free pattern, wherein a content ratio of a nonmagnetic metal in the nonmagnetic metal-oxide pattern is greater than a stoichiometric ratio and a concentration of the nonmagnetic metal is substantially uniform over the entire nonmagnetic metal-oxide pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern may generate atomic-magnetic moments, substantially perpendicular to the second surface of the uniform free pattern, in a surface portion including the second surface of the uniform free pattern.

In example embodiments of inventive concepts, the reference pattern may have a fixed magnetization direction parallel to the second surface of the uniform free pattern, a magnetization direction of the uniform free pattern may be changeable to a direction parallel or anti-parallel to the fixed magnetization direction of the reference pattern, and an amount of atomic-magnetic moments non-parallel to the second surface may be increased in the uniform free pattern by the nonmagnetic metal-oxide pattern.

In example embodiments of inventive concepts, the uniform free pattern may include iron (Fe) and cobalt (Co); and a content ratio of iron (Fe) in the uniform free pattern may be greater than a content ratio of cobalt (Co) in the uniform free pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern may include a tantalum-rich tantalum oxide.

In example embodiments of inventive concepts, the magnetic memory devices may further include a surface local region partially in the second surface of the uniform free pattern. The surface local region may include a material different from a magnetic material of the uniform free pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern may include a first portion of an amorphous state and a second portion of a crystalline state; and the surface local region contacts the second portion of the nonmagnetic metal-oxide pattern.

In example embodiments of inventive concepts, the surface local region may include an oxide formed by oxidizing a portion of the magnetic material of the uniform free pattern.

In example embodiments of inventive concepts, the magnetic memory devices may further include particles within the uniform free pattern, the particles including a material different from the uniform free pattern.

In example embodiments of inventive concepts, the reference pattern, the tunnel barrier pattern, and the uniform free pattern may correspond to a first reference pattern, a first tunnel barrier pattern, and a first uniform free pattern, respectively. In example embodiments of inventive concepts, the magnetic memory devices may further include: a second uniform free pattern including a first surface and a second surface opposite to each other; a second reference pattern on the first surface of the second uniform free pattern; and a second tunnel barrier pattern between the first surface of the second uniform free pattern and the second reference pattern, wherein the nonmagnetic metal-oxide pattern is between the second surface of the first uniform free pattern and the second surface of the second uniform free pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern may have a substantially uniform thickness.

In example embodiments of inventive concepts, the reference pattern may include a first magnetic material, the uniform free pattern may include a second magnetic material, and each of the first and second magnetic materials may include iron (Fe). A content ratio of iron (Fe) in the second magnetic material may be equal to or greater than that in the first magnetic material.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern may have a thickness of about 2 Å to about 20 Å.

In example embodiments of inventive concepts of inventive concepts, magnetic memory devices may include: a reference pattern on a substrate; a free pattern on the substrate; a tunnel barrier pattern between the free pattern and the reference pattern; and a surface local region partially in one surface of the free pattern and including a material different from the free pattern.

In example embodiments of inventive concepts, the surface local region may include an oxide formed by oxidizing a portion of the one surface of the free pattern or a nitride formed by nitrifying a portion of the one side of the free pattern.

In example embodiments of inventive concepts, the free pattern may include a first surface adjacent to the tunnel barrier pattern and a second surface opposite to the first surface, and the surface local region may be partially in of the second surface of the free pattern.

In example embodiments of inventive concepts, the magnetic memory devices may further include a thin pattern on the second surface of the free pattern.

In example embodiments of inventive concepts, the thin pattern may include a first portion having a first thickness and a second portion having a thinner second thickness than the first thickness. The surface local region may be directly below the second portion.

In example embodiments of inventive concepts, the thin pattern may include a first portion of an amorphous state and a second portion of a crystalline state. The surface local region may be directly below the second portion of the thin pattern.

In example embodiments of inventive concepts, the reference pattern, the tunnel barrier pattern, and the free pattern may correspond to a first reference pattern, a first tunnel barrier pattern, and a first free pattern, respectively. In example embodiments of inventive concepts, the magnetic memory devices may further include: a second free pattern including a first surface and a second surface opposite to each other; a second reference pattern on the first surface of the second free pattern; and a second tunnel barrier pattern between the first surface of the second free pattern and the second reference pattern, wherein the thin pattern is between the second surface of the first free pattern and the second surface of the second free pattern.

In example embodiments of inventive concepts, the magnetic memory devices may further include particles within the free pattern. The particles may include a material different from the free pattern.

In example embodiments of inventive concepts, the reference pattern may include a first magnetic material, the free pattern may include a second magnetic material, and each of the first and second magnetic materials may include iron (Fe). A content ratio of iron (Fe) in the second magnetic material may be equal to or greater than a content ratio of iron (Fe) in the first magnetic material.

In example embodiments of inventive concepts of inventive concepts, magnetic memory devices may include: a reference pattern on a substrate; a free pattern on the substrate; a tunnel barrier pattern between the free pattern and the reference pattern; and particles within the free pattern and including a nonmagnetic conductive material.

In example embodiments of inventive concepts, the free pattern may include a first surface and a second surface opposite to each other. The first surface of the free pattern may be adjacent to the tunnel barrier pattern, and the particles may be spaced from the first and second surfaces.

In example embodiments of inventive concepts, the free pattern may include a first surface adjacent to the tunnel barrier pattern and a second surface opposite to the first surface, and the reference pattern and the tunnel barrier pattern may correspond to a first reference pattern and a first tunnel barrier pattern, respectively. In example embodiments of inventive concepts, the magnetic memory devices may further include: a second reference pattern on the second surface of the free pattern; and a second tunnel barrier pattern between the second surface of the free pattern and the second reference pattern.

In example embodiments of inventive concepts, the reference pattern may includes a first magnetic material, the free pattern may include a second magnetic material, and each of the first and second magnetic materials may include iron (Fe). A content ratio of iron (Fe) in the second magnetic material may be equal to or greater than a content ratio of iron (Fe) in the first magnetic material

In example embodiments of inventive concepts of inventive concepts, magnetic memory devices may include: a uniform free pattern on a substrate and including a first surface and a second surface opposite to each other; a reference pattern on the substrate and having a fixed magnetization direction perpendicular to the second surface of the uniform free pattern; a tunnel barrier pattern between the first surface of the uniform free pattern and the reference pattern; and a uniform perpendicular nonmagnetic metal rich anisotropy enhanced pattern contacting the second surface of the uniform free pattern to generate atomic-magnetic moments perpendicular to the second surface of the uniform free pattern, wherein a magnetization direction of the uniform free pattern is changeable to parallel or anti-parallel to the fixed magnetization direction of the reference pattern.

In example embodiments of inventive concepts, the uniform free pattern may include iron (Fe) and cobalt (Co); and a content ratio of iron (Fe) in the uniform free pattern is greater than a content ratio of cobalt (Co) in the uniform free pattern.

In example embodiments of inventive concepts, the reference pattern may include: a reference perpendicular magnetic pattern having a first magnetization direction perpendicular to the second surface of the uniform free pattern; and a spin polarization pattern between the reference perpendicular magnetic pattern and the tunnel barrier pattern and having a second magnetization direction perpendicular to the second surface of the uniform free pattern.

In example embodiments of inventive concepts, the reference pattern may further include an exchange coupling pattern between the reference perpendicular magnetic pattern and the tunnel barrier pattern. The exchange coupling pattern may combine the first and second magnetization directions to be parallel or anti-parallel to each other.

In example embodiments of inventive concepts, the magnetic memory devices may further include a fixed perpendicular magnetic pattern on one surface of the perpendicular anisotropy enhanced pattern. The uniform perpendicular nonmagnetic metal rich anisotropy enhanced pattern may be between the uniform free pattern and the fixed perpendicular magnetic pattern, and the fixed perpendicular magnetic pattern may have a fixed magnetization direction perpendicular to the second surface of the uniform free pattern.

In example embodiments of inventive concepts, the magnetic memory devices may further include a free perpendicular magnetic pattern on one surface of the perpendicular anisotropy enhanced pattern. The uniform perpendicular nonmagnetic metal rich anisotropy enhanced pattern may be between the uniform free pattern and the free perpendicular magnetic pattern, and a magnetization direction of the free perpendicular magnetic pattern may be changeable to be parallel or anti-parallel to the fixed magnetization direction of the reference pattern.

In example embodiments of inventive concepts, a magnetic memory device may include a free pattern on a substrate, and having a first surface and a second surface opposite to each other, a reference pattern on the substrate, a tunnel barrier pattern between the first surface of the free pattern and the reference pattern, and a non-magnetic non-parallel magnetism generator contacting the free pattern, the non-magnetic non-parallel magnetism generator increasing a magnetization of the free layer in a direction non-parallel to the second surface.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator increases a number of magnetic moments non-parallel to the second surface.

In example embodiments of inventive concepts, the free pattern is made of an inplane magnetic material, whose magnetization, without an effect of the non-magnetic non-parallel magnetism generator is substantially in a direction parallel to the second surface.

In example embodiments of inventive concepts, at least one of a thickness and a material of at least one of the free pattern and the non-magnetic non-parallel magnetism generator is selected to convert a portion of the magnetization of the free pattern from the direction parallel to the second surface, to the direction non-parallel to the second surface.

In example embodiments of inventive concepts, the free pattern is a uniform material.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator includes a nonmagnetic metal-oxide pattern in contact with the second surface of the free pattern.

In example embodiments of inventive concepts, a content ratio of a nonmagnetic metal in the nonmagnetic metal-oxide pattern is greater than a stoichiometric ratio, and a concentration of the nonmagnetic metal is substantially uniform over the entire nonmagnetic metal-oxide pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern generates atomic-magnetic moments, substantially perpendicular to the second surface of the free pattern, in a surface portion including the second surface of the free pattern.

In example embodiments of inventive concepts, the reference pattern has a fixed magnetization direction parallel to the second surface of the free pattern, a magnetization direction of the free pattern is changeable to a direction parallel or anti-parallel to the fixed magnetization direction of the reference pattern, and an amount of atomic-magnetic moments non-parallel to the second surface is increased in the free pattern by the nonmagnetic metal-oxide pattern.

In example embodiments of inventive concepts, the free pattern includes iron (Fe) and cobalt (Co) and a content ratio of the iron (Fe) in the free pattern is greater than a content ratio of cobalt (Co) in the free pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern includes a tantalum-rich tantalum oxide.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator further includes a surface local region partially on the second surface of the free pattern, wherein the surface local region includes a material different from a magnetic material in the free pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern includes a first portion of an amorphous state and a second portion of a crystalline state and the surface local region contacts the second portion of the nonmagnetic metal-oxide pattern.

In example embodiments of inventive concepts, the surface local region includes an oxide formed by oxidizing a portion of the magnetic material of the free pattern.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator further includes particles within the free pattern, the particles including a material different from the free pattern.

In example embodiments of inventive concepts, the reference pattern, the tunnel barrier pattern, and the free pattern correspond to a first reference pattern, a first tunnel barrier pattern, and a first free pattern, respectively, and the magnetic memory device further includes a second free pattern including a first surface and a second surface opposite to each other, a second reference pattern on the first surface of the second free pattern, and a second tunnel barrier pattern between the first surface of the second free pattern and the second reference pattern, wherein the nonmagnetic metal-oxide pattern is between the second surface of the first free pattern and the second surface of the second free pattern.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern has a substantially uniform thickness.

In example embodiments of inventive concepts, the reference pattern includes a first magnetic material, the free pattern includes a second magnetic material, each of the first and second magnetic materials includes iron (Fe), and a content ratio of iron (Fe) in the second magnetic material is equal to or greater than that in the first magnetic material.

In example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern has a thickness of about 2 Å to about 20 Å.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator is a surface local region partially in one surface of the free pattern and including a material different from the free pattern.

In example embodiments of inventive concepts, the surface local region includes an oxide formed by oxidizing a portion of the one surface of the free pattern or a nitride formed by nitrifying a portion of the one side of the free pattern.

In example embodiments of inventive concepts, the free pattern includes a first surface adjacent to the tunnel barrier pattern and a second surface opposite to the first surface and the surface local region is partially in the second surface of the free pattern.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator further includes a thin pattern on the second surface of the free pattern.

In example embodiments of inventive concepts, the thin pattern includes a first portion having a first thickness and a second portion having a thinner second thickness than the first thickness and the surface local region is directly below the second portion.

In example embodiments of inventive concepts, the thin pattern includes a first portion of an amorphous state and a second portion of a crystalline state and the surface local region is directly below the second portion of the thin pattern.

In example embodiments of inventive concepts, the reference pattern, the tunnel barrier pattern, and the free pattern correspond to a first reference pattern, a first tunnel barrier pattern, and a first free pattern, respectively, and the magnetic memory device further includes a second free pattern including a first surface and a second surface opposite to each other, a second reference pattern on the first surface of the second free pattern, and a second tunnel barrier pattern between the first surface of the second free pattern and the second reference pattern, wherein the thin pattern is between the second surface of the first free pattern and the second surface of the second free pattern.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator further includes particles within the free pattern, wherein the particles include a material different from the free pattern.

In example embodiments of inventive concepts, the reference pattern includes a first magnetic material, the free pattern includes a second magnetic material, each of the first and second magnetic materials includes iron (Fe), and a content ratio of iron (Fe) in the second magnetic material is equal to or greater than a content ratio of iron (Fe) in the first magnetic material.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator includes a surface local region partially on the second surface of the free pattern, wherein the surface local region includes a material different from a magnetic material in the free pattern.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator includes particles within the free pattern and including a nonmagnetic conductive material.

In example embodiments of inventive concepts, the free pattern includes a first surface and a second surface opposite to each other, the first surface of the free pattern is adjacent to the tunnel barrier pattern, and the particles are spaced from the first and second surfaces.

In example embodiments of inventive concepts, the free pattern includes a first surface adjacent to the tunnel barrier pattern and a second surface opposite to the first surface, and the reference pattern and the tunnel barrier pattern correspond to a first reference pattern and a first tunnel barrier pattern, respectively, and the magnetic memory device further includes a second reference pattern on the second surface of the free pattern and a second tunnel barrier pattern between the second surface of the free pattern and the second reference pattern.

In example embodiments of inventive concepts, the reference pattern includes a first magnetic material, the free pattern includes a second magnetic material, each of the first and second magnetic materials includes iron (Fe) and a content ratio of iron (Fe) in the second magnetic material is equal to or greater than a content ratio of iron (Fe) in the first magnetic material.

In example embodiments of inventive concepts, the free pattern is made of a perpendicular magnetic material, whose magnetization, without an effect of the non-magnetic non-parallel magnetism generator is less substantially in a direction parallel to the second surface.

In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator is a perpendicular anisotropy enhanced pattern contacting the second surface of the free pattern to generate atomic-magnetic moments perpendicular to the second surface of the free pattern, wherein a magnetization direction of the free pattern is changeable to a direction parallel or anti-parallel to the fixed magnetization direction of the reference pattern.

In example embodiments of inventive concepts, the free pattern includes iron (Fe) and cobalt (Co) and a content ratio of iron (Fe) in the free pattern is greater than a content ratio of cobalt (Co) in the free pattern.

In example embodiments of inventive concepts, the reference pattern includes a reference perpendicular magnetic pattern having a first magnetization direction perpendicular to the second surface of the free pattern and a spin polarization pattern between the reference perpendicular magnetic pattern and the tunnel barrier pattern and having a second magnetization direction perpendicular to the second surface of the free pattern.

In example embodiments of inventive concepts, the reference pattern further includes an exchange coupling pattern between the reference perpendicular magnetic pattern and the tunnel barrier pattern and the exchange coupling pattern combines the first and second magnetization directions to be parallel or anti-parallel to each other.

In example embodiments of inventive concepts, a magnetic memory device may further include a fixed perpendicular magnetic pattern on one surface of the perpendicular anisotropy enhanced pattern, wherein the perpendicular anisotropy enhanced pattern is between the free pattern and the fixed perpendicular magnetic pattern and the fixed perpendicular magnetic pattern has a fixed magnetization direction perpendicular to the second surface of the free pattern.

In example embodiments of inventive concepts, the magnetic memory device further including a free perpendicular magnetic pattern on one surface of the perpendicular anisotropy enhanced pattern, wherein the perpendicular anisotropy enhanced pattern is between the free pattern and the free perpendicular magnetic pattern and a magnetization direction of the free perpendicular magnetic pattern is changeable to be parallel or anti-parallel to the fixed magnetization direction of the reference pattern.

In example embodiments of inventive concepts, an electronic system may include an input/output device, connected to a bus, configured to receive and send data externally, an interface, connected to the bus, configured to transmit data to and receive data from a communications network, a controller, connected to the bus, configured to process commands, and a magnetic memory device according to example embodiments of inventive concepts, connected to the bus, configured to store and retrieve data.

In example embodiments of inventive concepts, a memory card may include a magnetic memory device according to example embodiments of inventive concepts, connected to a bus, configured to store and retrieve data, and a controller including a processing unit connected to the bus, configured to control general operations of the memory card, a RAM, connected to the bus, configured as an operating memory of the processing unit, a host interface connected to the bus, configured to implement a data exchange protocol between the memory card and a host, a memory interface connected to the bus, configured to connect the memory controller with the memory device, and an error correction block connected to the bus, configured to detect and correct errors of data read from the magnetic memory device.

In example embodiments of inventive concepts, a method of manufacturing a magnetic memory device may include forming a magnetic tunneling junction including, forming a free pattern on a substrate, and having a first surface and a second surface opposite to each other, forming a reference pattern on the substrate, forming a tunnel barrier pattern between the first surface of the free pattern and the reference pattern, and forming a non-magnetic non-parallel magnetism generator contacting the free pattern, the non-magnetic non-parallel magnetism generator increasing a magnetization of the free pattern in a direction non-parallel to the second surface.

In example embodiments of inventive concepts, the free pattern is made of an inplane magnetic material, whose magnetization, without an effect of the non-magnetic non-parallel magnetism generator is substantially in a direction parallel to the second surface.

In example embodiments of inventive concepts, the free pattern is made of a perpendicular magnetic material, whose magnetization, without an effect of the non-magnetic non-parallel magnetism generator is less substantially in a direction parallel to the second surface.

In example embodiments of inventive concepts, a method of controlling a magnetization direction of a free pattern of magnetic tunneling junction may include forming the magnetic tunneling junction including, forming the free pattern having a thickness and a material on a substrate, and having a first surface and a second surface opposite to each other, forming a reference pattern on the substrate, forming a tunnel barrier pattern between the first surface of the free pattern and the reference pattern, and forming a non-magnetic non-parallel magnetism generator contacting the free pattern, the non-magnetic non-parallel magnetism generator having a thickness, forming a passivation pattern contacting the free pattern, the non-magnetic non-parallel magnetism generator having a thickness, and controlling at least one of the thickness and the material of at least one of the free pattern, a non-magnetic non-parallel magnetism generator, and the passivation pattern to convert a portion of the magnetization of the free pattern from a direction parallel to the second surface, to the direction non-parallel to the second surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of inventive concepts, and are incorporated in and constitute a part of this specification. The drawings illustrate example embodiments of inventive concepts and, together with the description, serve to explain principles of inventive concepts. In the drawings:

FIG. 1A is a sectional view of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 1B is an enlarged sectional view of the nonmagnetic metal oxide pattern, the free pattern, and the tunnel barrier pattern of the magnetic memory device shown inFIG. 1A;

FIG. 2A is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 2B is a sectional view illustrating another modification a magnetic memory device according to example embodiments of inventive concepts;

FIG. 2C is a sectional view illustrating further another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 2D is a sectional view illustrating further another modification of a magnetic memory device according to example embodiments of inventive concepts.

FIGS. 3A through 3D are sectional views illustrating a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts;

FIGS. 4A and 4B are sectional views illustrating a modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts;

FIGS. 5A and 5B are sectional views illustrating another modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts;

FIG. 5C is a flowchart illustrating a method of manufacturing the free layer ofFIG. 5B according to example embodiments of inventive concepts;

FIGS. 6A and 6B are sectional views illustrating further another modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts;

FIG. 6C is a sectional view illustrating further another modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts;

FIG. 7 is a sectional view of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 8A is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 8B is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 8C is a sectional view illustrating further another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 8D is a sectional view illustrating further another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIGS. 9A and 9B are sectional views illustrating manufacturing methods of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 9C is a flowchart illustrating another method of manufacturing the material layer ofFIG. 9A according to example embodiments of inventive concepts;

FIG. 10A is a sectional view illustrating a magnetic memory device according to example embodiments of inventive concepts;

FIG. 10B is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 10C is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 11A is a sectional view illustrating a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts;

FIG. 11B is a flowchart illustrating a method of forming the free layer ofFIG. 11A according to example embodiments of inventive concepts;

FIG. 11C is a flowchart illustrating another method of forming the free layer ofFIG. 11A according to example embodiments of inventive concepts;

FIG. 12 is a sectional view illustrating a magnetic memory device according to example embodiments of inventive concepts;

FIG. 13A is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 13B is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 13C is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 13D is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 13E is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts;

FIG. 14 is a block diagram illustrating an electronic system including a magnetic memory device according to example embodiments of inventive concepts; and

FIG. 15 is a block diagram illustrating a memory card including a magnetic memory device according to example embodiments of inventive concepts.

FIG. 16 is a flowchart illustrating methods of increasing the perpendicularity of a perpendicular free pattern according to example embodiments of inventive concepts.

FIG. 17 is a flowchart illustrating methods of controlling the parameters of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Example embodiments of inventive concepts will be described below in more detail with reference to the accompanying drawings. The inventive concept may, however, be embodied in different forms and should not be construed as limited to example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of inventive concepts to those skilled in the art.

In the drawings, the dimensions of layers and regions are exaggerated for clarity of illustration. It will also be understood that when a layer (or film) is referred to as being ‘on’ another layer or substrate, it may be directly on the other layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being ‘under’ another layer, it may be directly under, and one or more intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being ‘between’ two layers, it may be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.

FIG. 1A is a sectional view of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 1A, a firstinterlayer dielectric layer102 may be disposed on asubstrate100. A switching device (not shown) may be disposed on thesubstrate100. The switching device may be a field effect transistor (FET) or a diode. The firstinterlayer dielectric layer102 may be disposed on the entire surface of thesubstrate100 including the switching device. Alower contact plug104 may penetrate the firstinterlayer dielectric layer102. Thelower contact plug104 may be electrically connected to one end of the switching device. Thesubstrate100 may be a silicon substrate, a germanium substrate, or a silicon-germanium substrate. The firstinterlayer dielectric layer102 may include oxide, nitride and/or oxynitride. Thelower contact plug104 may include dopant-doped semiconductor (e.g., doped silicon, etc.), metal (e.g., titanium, tantalum, tungsten, copper, or aluminum, etc.), conductive metal nitride (e.g., a titanium nitride, a tantalum nitride, etc.) and/or a semiconductor-metal compound (e.g., a metal silicide, etc.)

Areference pattern120aand afree pattern130amay be disposed on the firstinterlayer dielectric layer102, and atunnel barrier pattern125amay be disposed between thereference pattern120aand thefree pattern130a. Thereference pattern120a, thetunnel barrier pattern125a, and thefree pattern130amay constitute a magnetic tunnel junction (MTJ) pattern. Thefree pattern130amay include a first surface adjacent to thetunnel barrier pattern125aand a second surface opposite to the first surface. The first and second surfaces of thefree pattern130amay be substantially parallel to the top surface of thesubstrate100. According to example embodiment of inventive concepts, as shown inFIG. 1A, thereference pattern120a, thetunnel barrier pattern125a, and thefree pattern130amay be sequentially stacked on the firstinterlayer dielectric layer102. In example embodiments, the first and second surfaces of thefree pattern130amay correspond to a bottom surface and a top surface of thefree pattern130a, respectively. Thereference pattern120amay be electrically connected to one terminal of the switching device through thelower contact plug104.

Thereference pattern120amay have a fixed magnetization direction parallel to the top surface of thesubstrate100. Thereference pattern120amay include a pinningpattern110a, a first pinnedpattern112a, anexchange coupling pattern114a, and/or a second pinnedpattern116a. The first pinnedpattern112amay be adjacent to the pinningpattern110aand may be disposed between the pinningpattern110aand the second pinnedpattern116a. Theexchange coupling pattern114amay be disposed between the first and second pinnedpatterns112aand116a. The second pinnedpattern116amay be adjacent to thetunnel barrier pattern125a. That is, the second pinnedpattern116amay be disposed between thetunnel barrier pattern125aand theexchange coupling pattern114a. The pinningpattern110amay fix a magnetization direction of the first pinnedpattern112ain one direction. The magnetization direction of the first pinnedpattern112amay be parallel to the top surface of thesubstrate100. A magnetization direction of the second pinnedpattern116amay be fixed anti-parallel to the magnetization direction of the first pinnedpattern112aby theexchange coupling pattern114a. The fixed magnetization direction of thereference pattern120amay be the magnetization direction of the second pinnedpattern116abeing adjacent to thetunnel barrier pattern125a. According to example embodiments of inventive concepts, as shown inFIG. 1A, when thereference pattern120ais disposed below thetunnel barrier pattern125a, thepining pattern110a, the first pinnedpattern112a, theexchange coupling pattern114a, and the second pinnedpattern116amay be sequentially stacked on the firstinterlayer dielectric layer102.

The pinningpattern110amay include an anti-ferromagnetic material. For example, the pinningpattern110amay include at least one of PtMn, IrMn, MnO, MnS, MnTe, or MnF. The first pinnedpattern112amay include a ferromagnetic material. For example, the first pinnedpattern112amay include at least one of CoFeB, CoFe, NiFe, CoFePt, CoFePd, CoFeCr, CoFeTb, CoFeGd, or CoFeNi. According to example embodiment of inventive concepts, a first magnetic material of the second pinnedpattern116amay include iron (Fe). For example, the first magnetic material of the second pinnedpattern116amay include at least one of CoFeB, CoFe, NiFe, CoFePt, CoFePd, CoFeCr, CoFeTb, CoFeGd, or CoFeNi. When the second pinnedpattern116amay include CoFeTb, the CoFeTb may have a content ratio of terbium (Tb) less than about 10% so that the second pinnedpattern116amay have a magnetization direction parallel to the top surface of thefree pattern130a. Similarly, when the second pinnedpattern116amay include CoFeGd, the CoFeGd may have a content ratio of gadolinium (Gd) less than about 10% so that the second pinnedpattern116amay have a magnetization direction parallel to the top surface of thefree pattern130a. Theexchange coupling pattern114amay include a rare metal. For example, theexchange coupling pattern114amay include at least one of Ru, Ir, or Rh.

Thetunnel barrier pattern125amay have a thickness less than a spin diffusion distance. Thetunnel barrier pattern125amay include an insulating material. For example, thetunnel barrier pattern125amay include at least one of magnesium oxide, titanium oxide, aluminum oxide, magnesium-zinc oxide, or magnesium-boron oxide.

Thefree pattern130amay have a changeable magnetization direction. That is, by a program operation, the magnetization direction of thefree pattern130amay be changed to a direction parallel or anti-parallel to the magnetization direction of the second pinnedpattern116a. Accordingly, the magnetization direction of thefree pattern130amay be horizontal to the top surface of thesubstrate100. By applying a program current through thereference pattern120a, thetunnel barrier pattern125a, and thefree pattern130a, the magnetization direction of thefree pattern130amay be changed. The magnetization direction of thefree pattern130amay be changed by spin torques of electrons in the program current.

For example, when the magnetization direction of thefree pattern130ais anti-parallel to that of the second pinnedpattern116a, a program current may be supplied from thefree pattern130ato thereference pattern120a. That is, electrons in the program current are supplied from thereference pattern120ato thefree pattern130a. The electrons in the program current may include major electrons and minor electrons. The major electrons may have spins parallel to the magnetization direction of the second pinnedpattern116aand the minor electrons may have spins anti-parallel to the magnetization direction of the second pinnedpattern116a. The major electrons may be accumulated in thefree pattern130aand the magnetization direction of thefree pattern130amay be changed to be parallel to that of the second pinnedpattern116aby spin torques of the accumulated major electrons.

When magnetization directions of the second pinnedpattern116aand thefree pattern130aare parallel to each other, a program current may be supplied from thereference pattern120ato thefree pattern130a. That is, electrons of the program current are supplied from thefree pattern130ato thereference pattern120a. Minor electrons anti-parallel to the magnetization direction of the second pinnedpattern116aamong electrons in the program current may be reflected by the magnetization direction of the second pinnedpattern116a, and the reflected minor electrons may be accumulated in thefree pattern130a. By spin torques of the accumulated minor electrons, the magnetization direction of thefree pattern130amay be changed to be anti-parallel to that of the second pinnedpattern116a.

The minimum current density to change a magnetization direction of thefree pattern130ais defined as a critical current density. Thefree pattern130amay include a second magnetic material. According to example embodiments of inventive concepts, the second magnetic material of thefree pattern130amay include iron (Fe). For example, the second magnetic material of thefree pattern130amay include at least one of CoFeB, CoFe, NiFe, CoFePt, CoFePd, CoFeCr, CoFeTb, CoFeGd, or CoFeNi. When thefree pattern130amay include CoFeTb, the CoFeTb may have a content ratio of terbium (Tb) less than about 10% so that thefree pattern130amay have a magnetization direction horizontal to the top surface of thefree pattern130a. Similarly, when thefree pattern130amay include CoFeGd, the CoFeGd may have a content ratio of gadolinium (Gd) less than about 10% so that thefree pattern130amay have a magnetization direction horizontal to the top surface of thefree pattern130a.

According to example embodiments of inventive concepts, a content ratio of iron (Fe) in the second magnetic material of thefree pattern130amay be equal to or greater than a content ratio of iron (Fe) in the first magnetic material of the second pinnedpattern116a. Accordingly, the MTJ pattern may have improved reliability.

A nonmagnetic metal-oxide pattern135amay be disposed on the second surface of thefree pattern130a. The nonmagnetic metal-oxide pattern135amay contact the second surface of thefree pattern130a. According to example embodiments of inventive concepts, as shown inFIG. 1A, the nonmagnetic metal-oxide pattern135amay be disposed on the top surface of thefree pattern130a. The nonmagnetic metal-oxide pattern135amay include a nonmagnetic metal and oxygen. A content ratio of the nonmagnetic metal in the nonmagnetic metal-oxide pattern135amay be greater than a stoichiometric ratio. That is, a content ratio of oxygen in the nonmagnetic metal-oxide pattern135amay be less than a stoichiometric ratio. For example, the nonmagnetic metal-oxide pattern135amay include a nonmagnetic metal-rich metal oxide. The nonmagnetic metal-rich metal oxide means a metal oxide in which a content ratio of the nonmagnetic metal is greater than a stoichiometric ratio. An oxygen content ratio in the nonmagnetic metal-rich metal oxide may be less than a stoichiometric ratio. As a result, even if the nonmagnetic metal-oxide pattern135ais oxide, the nonmagnetic metal-oxide pattern135amay have a lower resistivity. A concentration of the nonmagnetic metal in the nonmagnetic metal-oxide pattern135amay be substantially uniform over the entire nonmagnetic metal-oxide pattern135a, such that entire resistance of the nonmagnetic metal-oxide pattern135amay be reduced.

The nonmagnetic metal-oxide pattern135amay apply stress to thefree pattern130ain a direction parallel to the second surface of thefree pattern130a. The stress may be compressive force or tensile force. Accordingly, atomic-magnetic moments non-parallel to the second surface of thefree pattern130a(e.g., the top surface of the substrate100) may be increased in thefree pattern130a. As a result, the critical current density may be reduced so as to change the magnetization direction of thefree pattern130a. For example, when thefree pattern130ahas a positive magnetostriction constant, the nonmagneticmetal oxide layer135amay provide the compressive force to the second surface of thefree pattern130a, such that atomic-magnetic moments non-parallel to the second surface of thefree pattern130amay be generated in thefree pattern130a. This will be described in more detail with reference toFIG. 1B.

FIG. 1B is an enlarged sectional view of the nonmagnetic metal oxide pattern, the free pattern, and the tunnel barrier pattern of the magnetic memory device shown inFIG. 1A

Referring toFIG. 1B, thefree pattern130amay include a plurality of atomic-magnetic moments10a,10b, and10c. Since the nonmagneticmetal oxide layer135aapplies stress to thefree pattern130a, at least lattices of a surface portion including the second surface (e.g., the top surface) of thefree pattern130amay be distorted. Accordingly, atomic-magnetic moments non-parallel to the second surface of thefree pattern130amay be generated in thefree pattern130a.

Atomic-magnetic moments that are substantially perpendicular to the second surface, for example, by the nonmagnetic metal-oxide pattern135a, may be generated in the surface portion including the second surface of thefree pattern130a. Accordingly, an amount of the perpendicular atomic-magnetic moments10cmay be increased in the surface portion including the second surface of thefree pattern130a. Additionally, the atomic-magnetic moments10bdisposed directly below the perpendicular atomic-magnetic moments10cmay be inclined with respect to the second surface of thefree pattern130abecause of influence of the perpendicular atomic-magnetic moments10cof the surface portion. That is, by the nonmagnetic metal-oxide pattern135a, an amount of the inclined atomic-magnetic moments10bmay be increased. Additionally, thefree pattern130amay include the horizontal atomic-magnetic moments10abased on the second surface of thefree pattern130a. The magnetization direction of thefree pattern130amay be a net magnetization direction by a vector sum of the atomic-magnetic moments10a,10b, and10c. The magnetization direction of thefree pattern130amay be substantially parallel to the second surface of thefree pattern130a. At least the horizontal atomic-magnetic moments10amay be changed to be parallel to or anti-parallel to the magnetization direction of the second pinnedpattern116aby a program current.

As mentioned above, since the non-parallel atomic-magnetic moments are generated in thefree pattern130aby the nonmagnetic metal-oxide pattern135a, an amount of the non-parallel atomic-magnetic moments10band10cmay be increased in thefree pattern130a. An amount of the non-parallel atomic-magnetic moments10band10cin thefree pattern130acontacting the nonmagnetic metal-oxide pattern135amay be greater than that of initial non-parallel atomic-magnetic moments. The amount of the initial non-parallel atomic-magnetic moments means an amount of non-parallel atomic-magnetic moments in thefree pattern130awhen the nonmagnetic metal-oxide pattern135adoes not exist on the second surface of thefree pattern130a. That is, the amount of the initial non-parallel atomic-magnetic moments may be that of non-parallel atomic-magnetic moments in thefree pattern130awhen lattices of the surface portion including the second surface of thefree pattern130aare not distorted. For example, a portion of the perpendicular atomic-magnetic moments10cand a portion of the slant atomic-magnetic moments10bmay be included in the amount of the initial non-parallel atomic-magnetic moments.

An amount of the non-parallel atomic-magnetic moments is increased in the free pattern due to the nonmagnetic metal-oxide pattern135a, such that the critical current density may be reduced. For example, thefree pattern130amay have perpendicular demagnetization energy in a direction perpendicular to the second surface of thefree pattern130a. The perpendicular demagnetization energy may be applied as an energy barrier when the magnetization direction of thefree pattern130ais reversed. The non-parallel atomic-magnetic moments10band10cin thefree pattern130amay reduce the energy barrier. Accordingly, the critical current density for reversing the magnetization direction of thefree pattern130amay be reduced.

Additionally, as mentioned above, since the oxygen content ratio of the nonmagnetic metal-oxide pattern135ais less than a stoichiometric ratio, the nonmagnetic metal-oxide pattern135amay have a lower resistivity. Accordingly, a decrease of a magneto resistive (MR) ratio of the MTJ pattern including thereference pattern120a, thetunnel barrier pattern125a, and thefree pattern130amay be reduced.

As a result, due to the nonmagnetic metal-oxide pattern135a, a magnetic memory device having lower power consumption and/or improved reliability may be realized. Additionally, since the critical current density is reduced, sizes of a switching device for controlling the critical current density and/or transistors of a peripheral circuit may be reduced also. Accordingly, a magnetic memory device with a higher degree of integration may be realized.

According to example embodiments of inventive concepts, the magnetic material in thefree pattern130amay include iron (Fe) and cobalt (Co). In example embodiments, a content ratio of iron (Fe) in thefree pattern130amay be greater than a content ratio of cobalt (Co) in thefree pattern130a. Due to this, an amount of the non-parallel atomic-magnetic moments generated in thefree pattern130aby the nonmagnetic metal-oxide pattern135amay be increased. When thefree pattern130aincludes Fe and Co, thefree pattern130amay include at least one of CoFeB, CoFe, NiFe, CoFePt, CoFePd, CoFeCr, CoFeTb, CoFeGd, or CoFeNi. When thefree pattern130amay include CoFeTb, the CoFeTb may have a content ratio of terbium (Tb) less than about 10% so that thefree pattern130amay have a magnetization direction horizontal to the top surface of thefree pattern130a. Similarly, when thefree pattern130amay include CoFeGd, the CoFeGd may have a content ratio of Gd less than about 10% so that thefree pattern130amay have a magnetization direction horizontal to the top surface of thefree pattern130a.

According to example embodiments of inventive concepts, thefree pattern130amay have a thickness for including the non-parallel atomic-magnetic moments10band10cand the parallel atomic-magnetic moments10a. For example, thefree pattern130amay have the thickness of about 20 Å and about 50 Å. However, inventive concepts are not limited thereto. Thefree pattern130amay be thinner than about 20 Å or thicker than about 50 Å.

Referring toFIG. 1A, the nonmagnetic metal-oxide pattern135amay have a substantially uniform thickness. The nonmagnetic metal-oxide pattern135amay have a thin thickness. According to example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern135amay have a thickness of about 2 Å to about 20 Å. According to example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern135amay be in an amorphous state. According to example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern135amay include at least one of hafnium-rich hafnium oxide, tantalum-rich tantalum oxide, zirconium-rich oxide, chromium-rich chromium oxide, vanadium-rich vanadium oxide, molybdenum-rich molybdenum oxide, titanium-rich titanium oxide, tungsten-rich tungsten oxide, yttrium-rich yttrium oxide, magnesium-rich magnesium oxide, or zinc-rich zinc oxide.

According to example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern135aneed not be a nonmagnetic metal-oxide, but may also be a non-magnetic metal nitride. For example, thepattern135amay include at least one of a hafnium nitride, a tantalum nitride, a zirconium nitride, a chrome nitride, a vanadium nitride, a molybdenum nitride, a titanium nitride, a tungsten nitride, an yttrium nitride, a magnesium nitride, or a zinc nitride. According to example embodiments of inventive concepts, a content ratio of a nonmagnetic metal in the nonmagnetic metal nitride may be greater than a stoichiometric ratio.

According to example embodiments of inventive concepts, when thefree pattern130aincludes CoFeB, the nonmagnetic metal-oxide pattern135amay apply compression force to the second surface of thefree pattern130a, such that the non-parallel atomic-magnetic moments may be increased in thefree pattern130a. According to example embodiments of inventive concepts, the nonmagnetic metal-oxide pattern135amay include tantalum-rich oxide tantalum. For example, a stoichiometric ratio of the oxide tantalum may be Ta₂O₅. A content ratio of Ta in the tantalum-rich oxide tantalum may be greater than about 29% and less than about 100%.

Apassivation pattern140amay be disposed on the nonmagnetic metal-oxide pattern135a. The nonmagnetic metal-oxide pattern135amay be disposed between thepassivation pattern140aand thefree pattern130a. Thepassivation pattern140amay be formed of a conductive material. For example, thepassivation pattern140amay include metal. For example, thepassivation pattern140amay include at least one of Ru, Ta, Pd, Ti, Pt, Ag, Au, or Cu.

Afirst electrode105amay be disposed between thereference pattern120aand the firstinterlayer dielectric layer102. Asecond electrode145amay be disposed on thepassivation pattern140a. Thefirst electrode105amay contact the top surface of thelower contact plug104. The first andsecond electrodes105aand145amay include a conductive material having a suitable barrier property. For example, the first andsecond electrodes105aand145amay include a conductive metal nitride. For example, the first andsecond electrodes105aand145amay include at least one of titanium nitride, tantalum nitride, tungsten nitride, or titanium aluminum nitride. The first andsecond electrode105aand145amay be formed of the same material to each other or different materials from each other. However, inventive concepts are not limited thereto. For example, thefirst electrode105amay perform another function or may be formed of another material.

A secondinterlayer dielectric layer150 may be disposed on the entire surface of thesubstrate100 including thesecond electrode145a. Anupper contact plug152 may penetrate the secondinterlayer dielectric layer150 so as to contact thesecond electrode145a.Interconnections155 may be disposed on the secondinterlayer dielectric layer150 to contact theupper contact plug152. Theinterconnections155 may correspond to a bit line. Theupper contact plug152 may include at least one of metals (e.g., titanium, tantalum, copper, aluminum, or tungsten and so on) or conductive metal nitrides (e.g., titanium nitride, tantalum nitride and so on). Theinterconnections155 may include at least one of metals (e.g., titanium, tantalum, copper, aluminum, or tungsten and so on) or conductive metal nitrides (e.g., titanium nitride, tantalum nitride and so on).

Next, modifications of example embodiments will be described with reference to the drawings.

FIG. 2A is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 2A, as mentioned above, thefree pattern130amay have a first surface adjacent to thetunnel barrier pattern125aand a second surface opposite to the first surface. As shown inFIG. 2A, the first and second surfaces of thefree pattern130amay corresponding to the bottom and top surfaces of thefree pattern130a, respectively. A surfacelocal region160 may be partially formed on the second surface (e.g., the top surface) of thefree pattern130a. The partially forming of the surfacelocal region160 on the second surface of thefree pattern130amay mean that the surfacelocal region160 is formed on a portion of the second surface of thefree pattern130aand a surface portion including the portion of the second surface. The top surface of the surfacelocal region160 may be substantially coplanar to the second surface of thefree pattern130a. The surfacelocal region160 may include a material different from thefree pattern130a. According to example embodiments of inventive concepts, the surfacelocal region160 may include an oxide formed by oxidizing a portion of thefree pattern130a. Therefore, the surfacelocal region160 may include an oxide having oxygen element and the same elements as elements in thefree pattern130a.

A nonmagnetic metal-oxide pattern135a′ may contact the second surface of thefree pattern130a. The nonmagnetic metal-oxide pattern135a′ may be partially in a crystalline state. That is, the nonmagnetic metal-oxide pattern135a′ may include afirst portion137aof an amorphous state and asecond portion137bof a crystalline state. The surfacelocal region160 may be disposed directly below thesecond portion137bof the nonmagnetic metal-oxide pattern135a′. The surfacelocal region160 may contact the nonmagnetic metal-oxide pattern135a′. The surfacelocal region160 may contact thesecond portion137bof the nonmagnetic metal-oxide pattern135a′. The nonmagnetic metal-oxide pattern135a′ may have the same characteristics and may be formed of the same material as the nonmagnetic metal-oxide pattern135adescribed with reference toFIGS. 1A and 1B.

Due to the surfacelocal region160 including a material different from thefree pattern130a, atomic-magnetic moments non-parallel to the second surface of thefree pattern130amay be generated in a portion of thefree pattern130aadjacent to the surfacelocal region160. Accordingly, a critical current density required to reverse a magnetization direction of thefree pattern130amay be reduced by the non-parallel atomic-magnetic moments generated by the nonmagnetic metal-oxide pattern135a′ and the non-parallel atomic-magnetic moments generated by the surfacelocal region160. As a result, a magnetic memory device improved or optimized for lower power consumption and/or higher degree of integration may be realized

FIG. 2B is a sectional view illustrating another modification a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 2B, according to example embodiments, at least oneparticle180 may be disposed within thefree pattern130a. Theparticle180 may include a material different from thefree pattern130a. According to example embodiments, theparticle180 may include at least one of a nonmagnetic material, an oxide of a nonmagnetic material, a nitride of a nonmagnetic material, an oxide of a magnetic material, or a nitride of a magnetic material. For example, theparticle180 may include at least one of tantalum, zinc, hafnium, zirconium, magnesium, titanium, chrome, copper, an oxide thereof, a nitride thereof, an oxide of a magnetic material (e.g., an iron-nickel oxide, a cobalt-iron oxide and so on), or a nitride of a magnetic material (e.g., an iron-nickel nitride, a cobalt-iron oxide and so on). Theparticle180 may be spaced apart from the first and second surfaces (e.g., the top and bottom surfaces) of thefree pattern130a. That is, theparticle180 may be disposed at a given or predetermined depth from the top surface of thefree pattern130aand also may be disposed at a given or predetermined level from the bottom surface of thefree pattern130a.

Since theparticle180 includes a material different from thefree pattern130a, atomic-magnetic moments non-parallel to the first and second surfaces of thefree pattern130amay be generated in thefree pattern130aaround theparticle180. Accordingly, the critical current density may be reduced by the non-parallel atomic-magnetic moments generated by theparticles180 and the nonmagnetic metal-oxide pattern135a, such that a magnetic memory device improved or optimized for lower power consumption and/or higher degree of integration may be realized.

According to example embodiments of inventive concepts, thefree pattern130amay include both the surfacelocal region160 ofFIG. 2A and theparticle180 of theFIG. 2B.

In addition, according to the magnetic memory device described with reference toFIG. 1A, thereference pattern120a, thetunnel barrier pattern125a, and thefree pattern130amay be sequentially stacked on the firstinterlayer dielectric layer102. Unlike this, thepatterns120a,125a, and130amay be stacked in a different order. This will be described with reference to the drawings.

FIG. 2C is a sectional view illustrating further another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 2C, afirst electrode105a, afree pattern130a, atunnel barrier pattern125a, areference pattern120a, and asecond electrode145amay be sequentially stacked on a firstinterlayer dielectric layer102. In example embodiments, the first surface contacting thetunnel barrier pattern125aof thefree pattern130amay correspond to the top surface of thefree pattern130a, and the second surface opposite to the first surface of thefree pattern130amay correspond to the bottom surface of thefree pattern130a. In example embodiments, the nonmagnetic metal-oxide pattern135amay be disposed between thefree pattern130aand thefirst electrode105a, and may contact the bottom surface of thefree pattern130a. Apassivation pattern140amay be disposed between thefirst electrode105aand the nonmagnetic metal-oxide pattern135a. According to example embodiments of inventive concepts, thepassivation pattern140amay be omitted. According to this modification, a second pinnedpattern116a, anexchange coupling pattern114a, a first pinnedpattern112a, and a pinnedpattern110amay be sequentially stacked on thetunnel barrier pattern125a. As shown inFIG. 2C, thefree pattern130amay include theparticles180 shown inFIG. 2B.

FIG. 2D is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts. An MTJ pattern of the magnetic memory device according to this modification may include two free patterns, two tunnel barrier patterns, and two reference patterns. As described below, thereference pattern120a, thetunnel barrier pattern125a, and thefree pattern130aofFIG. 1A may correspond to thefirst reference pattern120a, the firsttunnel barrier pattern125a, and the firstfree pattern130a, respectively.

Referring toFIG. 2D, afirst electrode105amay be disposed on a firstinterlayer dielectric layer102. Afirst reference pattern120a, a firsttunnel barrier pattern125a, and a firstfree pattern130amay be sequentially stacked on thefirst electrode105a. A nonmagnetic metal-oxide pattern135amay be disposed on the firstfree pattern130a. A secondfree pattern300a, a secondtunnel barrier pattern305a, and asecond reference pattern315amay be sequentially disposed on the nonmagnetic metal-oxide pattern135a. The MTJ pattern may include thefirst reference pattern120a, the firsttunnel barrier pattern125a, the firstfree pattern130a, the nonmagnetic metal-oxide pattern135a, the secondfree pattern300a, the secondtunnel barrier pattern305a, and thesecond reference pattern315a.

The secondfree pattern300amay have a first surface and a second surface opposite to each other. The first surface of the secondfree pattern300amay contact the secondtunnel barrier pattern305aand the second surface of the secondfree pattern300amay contact the nonmagnetic metal-oxide pattern135a. The first and second surfaces of the secondfree pattern300amay correspond to the top and bottom surfaces of the secondfree pattern300a, respectively. The first and second surfaces of the secondfree pattern300amay be horizontal to the top surface of thesubstrate100. As described with reference toFIG. 1A, the first surface of the firstfree pattern130amay be adjacent to the firsttunnel barrier pattern125aand the second surface of the secondfree pattern130amay contact the nonmagnetic metal-oxide pattern135a. Accordingly, the nonmagnetic metal-oxide pattern135amay be disposed between the second surface (e.g., the top surface) of the firstfree pattern130aand the second surface (e.g., the bottom substrate) of the secondfree pattern300a. For example, the bottom and top surfaces of the nonmagnetic metal-oxide pattern135amay contact the second surface (e.g., the top surface) of the firstfree pattern130aand the second surface (e.g., the bottom surface) of the secondfree pattern300a, respectively. Since the nonmagnetic metal-oxide pattern135acontacts the secondfree pattern300a, atomic-magnetic moments non-parallel to the second surface of the secondfree pattern300amay be increased in the secondfree pattern300a. Accordingly, a critical current density may be reduced.

The secondfree pattern300amay have a magnetization direction, which is changeable and parallel to the first and second surfaces of the firstfree pattern130a. As shown in the drawings, the magnetization direction of the secondfree pattern300amay be anti-parallel to the magnetization direction of the firstfree pattern130a. This may be caused by a magnetostatic field or a stray field generated from the first and secondfree patterns130aand300a. The secondfree pattern300amay be formed of the same magnetic material as the firstfree pattern130a. The secondtunnel barrier pattern305amay include at least one of magnesium oxide, titanium oxide, aluminum oxide, magnesium-zinc oxide, or magnesium-boron oxide. An electrical resistance of the firsttunnel barrier pattern125amay be different from that of the secondtunnel barrier pattern305a. Accordingly, since the first magnetic resistance ratio by thefirst reference pattern120a, a firsttunnel barrier pattern125a, and the firstfree pattern130abecomes different from a second magnetic resistance ratio by thesecond reference pattern315a, the secondtunnel barrier pattern305a, and the secondfree pattern300a, such that logic data may be written in the MTJ pattern including the first and secondfree patterns130aand305aor the logic data stored in the MTJ pattern may be read. For example, when the first and secondtunnel barrier patterns125aand305aare formed of the same material, as shown in the drawings, the firsttunnel barrier pattern125amay have a thickness different from the secondtunnel barrier pattern305a. According to example embodiments of inventive concepts, the firsttunnel barrier pattern125amay have a dielectric material having a lower resistivity than the secondtunnel barrier pattern305a. Therefore, an electrical resistance of the firsttunnel barrier pattern125aand an electrical resistance of the secondtunnel barrier pattern305amay be adjusted differently by adjusting the thicknesses of the first and secondtunnel barrier patterns125aand305aand/or the resistivities of the dielectric materials included in the first and secondtunnel barrier patterns125aand305a. According to example embodiments of inventive concepts, when the first and secondtunnel barrier patterns125aand305amay be formed of the same material and the firsttunnel barrier pattern125amay be thicker than the secondtunnel barrier pattern305a, the firstfree pattern130amay substantially be a storage element for storing logic data.

Thesecond reference pattern315amay include a pinningpattern313a, a first pinnedpattern311a, anexchange coupling pattern309a, and a second pinnedpattern307a. A first pinnedpattern311aof thesecond reference pattern315amay be disposed between the pinningpattern313aand the secondtunnel barrier pattern305a, and a second pinnedpattern307aof thesecond reference pattern315amay be disposed between the first pinnedpattern311aand the secondtunnel barrier pattern305a. Theexchange coupling pattern309aof thesecond reference pattern315amay be disposed between the first and second pinnedpatterns311aand307a. The first pinnedpattern311aof thesecond reference pattern315amay contact the pinningpattern313a, and the second pinnedpattern307aof thesecond reference pattern315amay contact the top surface of the secondtunnel barrier pattern305a. The magnetization direction of the first pinnedpattern311aof thesecond reference pattern315amay have a fixed magnetization direction by the pinningpattern313a. The magnetization direction of the first pinnedpattern311aof thesecond reference pattern315amay be substantially parallel to the first and second surfaces of the firstfree pattern130a. The magnetization direction of the second pinnedpattern307aof thesecond reference pattern315amay be fixed in anti-parallel to the magnetization direction of the first pinnedpattern311aby theexchange coupling pattern309a.

The pinningpattern313aof thesecond reference pattern315amay include an anti-ferromagnetic material. For example, the pinningpattern313aof thesecond reference pattern315amay include at least one of PtMn, IrMn, MnO, MnS, MnTe, or MnF. The first pinnedpattern311aof thesecond reference pattern315amay include a ferromagnetic material. For example, the first pinned pattern31 la of thesecond reference pattern315amay include at least one of CoFeB, CoFe, NiFe, or CoFeNi. Theexchange coupling pattern309aof thesecond reference pattern315amay include a rare metal. For example, theexchange coupling pattern309aof thesecond reference pattern315amay include at least one of Ru, Ir, or Rh.

Thesecond electrode145amay be disposed on thesecond reference pattern315a. According to this modification, thepassivation pattern140aofFIG. 1A may be omitted.

According to example embodiments of inventive concepts, as shown inFIG. 2D, the second pinnedpattern116aof thefirst reference pattern120aadjacent to the firsttunnel barrier pattern125amay have a magnetization direction parallel to a magnetization direction of the second pinnedpattern307aof thesecond reference pattern315aadjacent to the secondtunnel barrier pattern305a. After applying heat of a higher temperature than a blocking temperature of the pinningpatterns110aand313aand then providing external magnetization, magnetization directions of the second pinnedpatterns116aand307aof the first andsecond reference patterns120aand315amay be arranged to be in parallel. The blocking temperature may be a critical temperature at which anti-ferromagnetic materials in the pinningpatterns110aand313amay lose their properties. For example, when the heat of a higher temperature than the blocking temperature is applied, atomic-magnetic moments in the anti-ferromagnetic materials may be arranged in a random direction.

An operation method of the magnetic memory device will be described. During one program operation, a program current from thesecond electrode145ato thefirst electrode105amay be provided. In example embodiments, electrons in the program current may transfer from thefirst electrode105ato thesecond electrode145a. The electrons in the program current may penetrate the second pinnedpattern116aof thefirst reference pattern120a. The electrons penetrating the second pinnedpattern116aof thefirst reference pattern120amay include major electrons and minor electrons. The major electrons may have spins parallel to the magnetization direction of the second pinnedpattern116aof thefirst reference pattern120aand the minor electrons may have spins anti-parallel to the magnetization direction of the second pinnedpattern116aof thefirst reference pattern120a. The major electros may be accumulated in the firstfree pattern130a, thereby reversing the magnetization direction of the firstfree pattern130a. The magnetization direction of the secondfree pattern300amay be coupling to the magnetization direction of the firstfree pattern130aby the magnetostatic field or the stray field, such that the magnetization direction of the secondfree pattern300amay be reversed when the magnetization direction of the firstfree pattern130ais reversed. The magnetization directions of the second pinnedpatterns116aand307aof the first andsecond reference patterns120aand315aare parallel to each other, such that the minor electrons may be reflected by the magnetization direction of thesecond reference pattern315aafter penetrating the nonmagnetic metal-oxide pattern135aand the secondfree pattern300a. The reflected minor electrons may be accumulated in the secondfree pattern300a, thereby helping the magnetization direction of the secondfree pattern300ato be reversed. As a result, the magnetization directions of the first and secondfree patterns130aand300acombined in an anti-parallel direction can be reversed by the major electrons penetrating the second pinnedpattern116aof thefirst reference pattern120aand the minor electrons reflected to the second pinnedpattern307aof thesecond reference pattern315a. Accordingly, a critical current density may be reduced.

According to example embodiments of inventive concepts, a program current may be supplied from thefirst electrode105ato thesecond electrode145a. In example embodiments, major electrons penetrating the second pinnedpattern307aof thesecond reference pattern315amay be accumulated in the secondfree pattern300asuch that they contribute to reversing the magnetization direction of the secondfree pattern300aand also minor electrons reflected to the second pinnedpattern116aof thefirst reference pattern120amay be accumulated in the firstfree pattern130asuch that they contribute to reversing the magnetization direction of the firstfree pattern130a. In example embodiments, the major electrons penetrating the second pinnedpattern307aof thesecond reference pattern315amay have spins parallel to the magnetization direction of the second pinnedpattern307aof thesecond reference pattern315a, and the minor electrons reflected to the second pinnedpattern116aof thefirst reference pattern120amay have spins anti-parallel to the magnetization direction of the second pinningpattern116a.

As a result, according to this modification, an amount of non-parallel atomic-magnetic moments in the first and secondfree patterns130aand300ais increased by the nonmagnetic metal-oxide pattern135a, so that the critical current density may be reduced. Additionally, during one program operation, the major electrons penetrating the second pinnedpatterns116aof thefirst reference pattern120aand the minor electrons reflected to the second pinnedpattern307aof thesecond reference pattern315aare all used to reverse the magnetization directions of the first and secondfree patterns130aand300a. As a result, a critical current density may be further reduced.

According to example embodiments of inventive concepts, the firstfree pattern130aofFIG. 2D may include the surface local region shown inFIG. 2A and/or theparticles180 shown inFIG. 2B. According to example embodiments of inventive concepts, the secondfree pattern300amay includeparticles180 shown inFIG. 2B.

Next, a method of manufacturing a magnetic memory device according to example embodiments will be described with reference to the drawings.

FIGS. 3A through 3D are sectional views illustrating a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 3A, a firstinterlayer dielectric layer102 may be formed on asubstrate100 and alower contact plug104 penetrating the firstinterlayer dielectric layer102 may be formed. Next, a first electrodeconductive layer105, areference layer120, atunnel barrier layer125, and/or afree layer130 may be sequentially formed on the firstinterlayer dielectric layer102. Thereference layer120 may include a pinninglayer110, a first pinnedlayer112, anexchange coupling layer114, and/or a second pinnedlayer116, which are sequentially stacked.

Anonmagnetic metal layer133 may be formed on thefree layer130. Thenonmagnetic metal layer133 may be formed by a sputtering process. Alternatively, thenonmagnetic metal layer133 may be formed through a chemical vapor deposition (CVD) process or an atomic layer deposition (ALD) process.

Referring toFIG. 3B, a nonmagneticmetal oxide layer135 may be formed by oxidizing thenonmagnetic metal layer133. Thenonmagnetic metal layer133 may be oxidized by a natural oxidation, a radical oxidation process or a plasma oxidation process. In example embodiments, oxygen amount supplied to thenonmagnetic metal layer133 may be less than a stoichiometric ratio. Accordingly, the nonmagneticmetal oxide layer135 may be formed of a nonmagnetic metal-rich metal oxide. According to example embodiments of inventive concepts, the nonmagneticmetal oxide layer135 may be thinly formed with a thickness of about 2 Å to about 20 Å.

The nonmagneticmetal oxide layer135 may be formed by other methods. For example, the nonmagneticmetal oxide layer135 may be formed by a CVD process or an ALD process. In example embodiments, a supply amount of metal source gas and a supply amount of oxygen source gas may be adjusted to increase a content ratio of a nonmagnetic metal in the nonmagneticmetal oxide layer135 to be higher than a stoichiometric ratio. For example, a supply amount of a metal source may be increased and an amount of oxygen source gas may be decreased.

Referring toFIGS. 3C and 3D, apassivation layer140 and a second electrodeconductive layer145 may be sequentially formed on the nonmagneticmetal oxide layer135. Next, the second electrodeconductive layer145, thepassivation layer140, the nonmagneticmetal oxide layer135, thefree layer130, thetunnel barrier layer125, thereference layer120, and the first electrodeconductive layer105 may be sequentially patterned. Accordingly, as shown inFIG. 3D, the sequentially stackedfirst electrode105a,reference pattern120a,tunnel barrier pattern125a,free pattern130a, nonmagnetic metal-oxide pattern135a,passivation pattern140a, and second electrodeconductive layer145 may be formed on the firstinterlayer dielectric layer102.

Next, the secondinterlayer dielectric layer150, theupper contact plug152, and theinterconnection155 ofFIG. 1A may be sequentially formed. Therefore, the magnetic memory device ofFIG. 1A is produced.

Next, a method of manufacturing the magnetic memory device shown inFIG. 2A will be described. During description of the manufacturing method, overlapping description will be omitted for convenience.

FIGS. 4A and 4B are sectional views illustrating a modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 4A, anonmagnetic metal layer133′ may be formed on afree layer130. Thenonmagnetic metal layer133′ may include afirst portion132aof an amorphous state and asecond portion132bof a crystalline state. Thenonmagnetic metal layer133′ may be formed through a sputtering process. When thenonmagnetic metal layer133′ is deposited through a sputtering process, it may be partially in a crystalline state. According to example embodiments of inventive concepts, after thenonmagnetic metal layer133′ is deposited through a sputtering process, an annealing process may be performed on thenonmagnetic metal layer133′ such thatnonmagnetic metal layer133′ may be partially in a crystalline state.

Referring toFIGS. 4A and 4B, a nonmagneticmetal oxide layer135′ may be formed by oxidizing thenonmagnetic metal layer133′. An oxidation speed of thefirst portion132ain the amorphous state may be different from that of thesecond portion132bin the crystalline state. The oxidation speed of thesecond portion132bin the crystalline state may be faster than that of thefirst portion132ain the amorphous state. Accordingly, a portion of the top surface of thefree layer130 may be oxidized by oxygen supplied through thesecond portion132b. As a result, a surfacelocal region160 may be partially formed on the top surface of thefree layer130. A content ratio of a nonmagnetic metal in the nonmagneticmetal oxide layer135′ may be higher than a stoichiometric ratio. The nonmagneticmetal oxide layer135′ may include a first portion of an amorphous state and a second portion of a crystalline state. That is, thefirst portion132aof thenonmagnetic metal layer133′ is oxidized such that it may be formed as a first portion (of an amorphous state) of the nonmagneticmetal oxide layer135′ and thesecond portion132bof thenonmagnetic metal layer133′ is oxidized such that it may be formed as a second portion (of a crystalline state) of the nonmagneticmetal oxide layer135′. A method below will be performed as described with reference toFIGS. 3C and 3D.

Next, a manufacturing method of the magnetic memory device ofFIG. 2B will be described.

FIGS. 5A and 5B are sectional views illustrating another modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 5A, a first submagnetic layer128amay be formed on atunnel barrier layer125. The first submagnetic layer128amay be formed of the same material as thefree pattern130adescribed with reference toFIG. 1A. At least oneparticle180 may be formed on the first submagnetic layer128a. Theparticle180 may be formed through a sputtering process. Theparticles180 are spaced apart from each other on the first submagnetic layer128a.

Referring toFIG. 5B, a second submagnetic layer128bmay be formed on the first submagnetic layer128aand theparticle180. Accordingly, theparticles180 may be surrounded by the first and second submagnetic layers128aand128b. The second submagnetic layer128bmay be formed of the same magnetic material as the first submagnetic layer128a. The first and second submagnetic layers128aand128bmay be included in thefree layer130. Accordingly, theparticle180 may be disposed in thefree layer130.

Thefree layer130 including theparticle180 may be formed through another method. This will be described with reference to a flowchart ofFIG. 5C.

FIG. 5C is a flowchart illustrating another method of manufacturing the free layer ofFIG. 5B.

Referring toFIG. 5C, an alloy including a magnetic material and a particle material may be prepared (S51). The alloy may include a magnetic material included in thefree pattern130adescribed with reference toFIG. 1A and a particle material included in theparticle180 described with reference toFIG. 2B. A content ratio of the magnetic material in the alloy may be far higher than that of the particle material. A free layer including particles therein may be formed by performing a sputtering process that uses the alloy as a target (S52). During the sputtering process using the alloy, a large amount of magnetic material may be deposited, and a small amount of particle material may be deposited simultaneously. Since the particle material is different from the magnetic material, the particle material may be segmented in the magnetic material, such that the particle may be formed in the magnetic material. The deposited magnetic material corresponds to the free layer.

Next, a method of manufacturing the magnetic memory device shown inFIG. 2C will be described with reference to the drawings.

FIGS. 6A and 6B are sectional views illustrating another modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 6A, a first electrodeconductive layer105 may be formed on a firstinterlayer dielectric layer102, and apassivation layer140 may be formed on the first electrodeconductive layer105. Next, anonmagnetic metal layer133 may be formed on thepassivation layer140. According to example embodiments of inventive concepts, thepassivation layer140 may be omitted. In example embodiments, thenonmagnetic metal layer133 may be formed on the first electrodeconductive layer105.

Referring toFIG. 6B, a nonmagneticmetal oxide layer135 may be formed by oxidizing thenonmagnetic metal layer133. Since an oxidation method of the nonmagneticmetal oxide layer135 is described in detail with reference toFIG. 3B, its description will be omitted here. The nonmagneticmetal oxide layer135 may be formed through another method described with reference toFIG. 3B.

Afree layer130, atunnel barrier layer125, areference layer120, and/or a second electrodeconductive layer145 are sequentially formed on the nonmagneticmetal oxide layer135. Thereference layer120 may include a pinninglayer110, a first pinnedlayer112, anexchange coupling layer114, and/or a second pinnedlayer116. The pinninglayer110 may be formed at the uppermost position in relation to thesubstrate100. The first pinnedlayer112 may be formed between the pinninglayer110 and thetunnel barrier layer125, and the second pinnedlayer116 may be formed between the first pinnedlayer112 and thetunnel barrier layer125. Theexchange coupling layer114 may be formed between the first and second pinnedlayers112 and116.

Next, thelayers145,120,125,130,135,140, and105 are sequentially patterned, as shown inFIG. 2C, to form the sequentiallystacked patterns105a,140a,135a,130a,125a,120a, and145a. Next, the secondinterlayer dielectric layer150, theupper contact plug152, and theinterconnection155 ofFIG. 2C may be sequentially formed. Therefore, the magnetic memory device ofFIG. 2C is realized.

Next, a method of manufacturing a magnetic memory device ofFIG. 2D will be described with reference to the drawings.

FIG. 6C is a sectional view illustrating further another modification of a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 6C, a first electrodeconductive layer105, areference layer120, atunnel barrier layer125, afree layer130, a nonmagneticmetal oxide layer135, a secondfree layer300, a secondtunnel barrier layer305, asecond reference layer315, and a second electrodeconductive layer145 are sequentially formed on the firstinterlayer dielectric layer102. Thesecond reference layer315 may include a pinninglayer313, anexchange coupling layer309, and a second pinnedlayer307. The pinninglayer313 may be formed at the uppermost in thesecond reference layer315. The first pinnedlayer311 may be formed between the pinninglayer313 and the secondtunnel barrier layer305. The second pinnedlayer307 may be formed between the first pinnedlayer311 and the secondtunnel barrier layer305. Theexchange coupling layer309 may be formed between the first and second pinnedlayers307 and311.

The second electrodeconductive layer145, thesecond reference layer315, the secondtunnel barrier layer305, the secondfree layer300, the nonmagneticmetal oxide layer135, the firstfree layer130, the firsttunnel barrier layer125, thefirst reference layer120, and the first electrodeconductive layer105 are sequentially patterned such that the MTJ pattern ofFIG. 2D may be formed. The subsequent processes are the same as those described with reference toFIG. 3D.

In example embodiments, like reference numerals refer to like elements. Additionally, their overlapping description will be omitted for convenience.

FIG. 7 is a sectional view of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 7, thefree pattern130amay include a first surface and a second surface opposite to each other. The first surface of thefree pattern130amay be adjacent to thetunnel barrier pattern125a. InFIG. 7, the first and second surfaces of thefree pattern130amay correspond to the bottom and top surfaces, respectively.

A surfacelocal region170 may be partially formed on the second surface (e.g., the top surface) of thefree pattern130a. The second surface of thefree pattern130amay include a first portion with the surfacelocal region170 and a second portion without the surfacelocal region170. The second portion of the second surface of thefree pattern130amay be formed of a magnetic material. The surfacelocal region170 may be formed in a portion of the second surface of thefree pattern130aand a portion of the surface portion adjacent thereto. The top surface of the surfacelocal region170 may be substantially coplanar with the second surface of thefree pattern130a. The surfacelocal region170 may be formed of a material different from thefree pattern130a. According to example embodiments of inventive concepts, the surfacelocal region170 may include an oxide formed by oxidizing a portion of thefree pattern130a. That is, the surfacelocal region170 may include an oxide including elements included in thefree pattern130aand oxygen element. Unlike this, the surfacelocal region170 may include a nitride formed by nitrifying a portion of thefree pattern130a. That is, the surfacelocal region170 may include a nitride including elements in thefree pattern130aand nitrogen element. Since the surfacelocal region170 is formed of a different material than thefree pattern130a, atomic-magnetic moments non-parallel to the second surface of thefree pattern130amay be generated in a portion of thefree pattern130aadjacent to the surfacelocal region170. Accordingly, the critical current density (e.g., a minimum current density for reversing a magnetization direction of thefree pattern130a) may be reduced. As a result, a magnetic memory device improved or optimized for lower power consumption and/or higher degree of integration may be realized.

Athin pattern235amay be disposed on the second surface of thefree pattern130a. Thethin pattern235amay contact the second surface of thefree pattern130a. According to example embodiments of inventive concepts, thethin pattern235amay include a first portion having a first thickness and a second portion having a second thickness thinner than the first thickness. The surfacelocal region170 may be disposed directly below the second portion of thethin pattern235ahaving a relatively thinner thickness (e.g., the second thickness). The surfacelocal region170 may contact thethin pattern235a. Thethin pattern235amay have a thin thickness to reduce or minimize the increase of a magnetic resistance ratio and/or the increase of an MTJ pattern resistance. For example, as mentioned above, thethin pattern235amay have a thickness of about 2 Å to about 20 Å. When thethin pattern235amay have an irregular thickness, a thickness of the first portion (a relatively thick portion) of thethin pattern235amay be greater than about 2 Å and equal to or less than about 20 Å, and the second portion (a relatively thin portion) of thethin pattern235amay be equal to or more than about 2 Å and less than about 20 Å. Thethin pattern235amay include an oxide or a nitride. Thethin pattern235amay include a nonmagnetic metal oxide or a nonmagnetic metal nitride. For example, thethin pattern235amay include at least one of tantalum oxide, zinc oxide, hafnium oxide, zirconium oxide, magnesium oxide, titanium oxide, chrome oxide, copper oxide, chrome nitride, tantalum nitride, hafnium nitride, titanium nitride, or copper nitride. Apassivation pattern140aand asecond electrode145amay be sequentially formed on thethin pattern235a.

Next, other example embodiments of inventive concepts will be described with reference to the drawings.

FIG. 8A is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 8A, athin pattern235a′ may contact the second surface of thefree pattern130a. Thethin pattern235a′ may include afirst portion237aof an amorphous state and asecond portion237bof a crystalline state. The surfacelocal region170 may be disposed directly below thesecond portion237band may contact thesecond portion237b. Thethin pattern235a′ may substantially have a uniform thickness. For example, thethin pattern235a′ may have a thickness of about 2 Å to about 20 Å. Thethin pattern235a′ may be formed of the same material as thethin pattern235adescribed with reference toFIG. 7.

FIG. 8B is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 8B, at least oneparticle180 may be disposed within thefree pattern130a. Theparticle180 may be formed of the same material described with reference toFIG. 2B. The critical current density may be reduced more by the non-parallel atomic-magnetic moments generated by the surfacelocal region170 and theparticle180. InFIG. 8B, thethin pattern235amay be replaced with thethin pattern235a′ ofFIG. 8A.

FIG. 8C is a sectional view illustrating further another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 8C, according to this modification, a thin pattern may be omitted. In example embodiments, the surfacelocal region170 may contact thepassivation pattern140a. According to example embodiments of inventive concepts, thepassivation pattern140amay be omitted and the surfacelocal region170 may contact thesecond electrode145a.

FIG. 8D is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 8D, according to this modification, an MTJ pattern may include afirst reference pattern120a, a firsttunnel barrier pattern125a, a firstfree pattern130a, athin pattern235a′, a secondfree pattern300a, a secondtunnel barrier pattern305a, and asecond reference pattern315a, which are sequentially stacked on a firstinterlayer dielectric layer102. Afirst electrode105amay be disposed between thefirst reference pattern120aand the firstinterlayer dielectric layer102, and asecond electrode145amay be disposed on thesecond reference pattern315a. The firstfree pattern130amay include a surfacelocal region170 formed on a portion of the top surface of the firstfree pattern130a. As described with reference toFIG. 2D, during one program operation, minor electrons reflected by the second pinnedpattern307aof thesecond reference pattern315amay contribute to reversing the magnetization direction of the secondfree pattern300a.

As a result, according to this modification, a critical current density may be reduced by the surfacelocal region170. Additionally, during one program operation, by the MTJ pattern including at least thefree patterns130aand300aand thereference patterns120aand315a, major electrons and minor electros are used to reverse the magnetization directions of the first and secondfree patterns130aand300a. Thereby, a critical current density may be further reduced.

According to example embodiments of inventive concepts, theparticle180 ofFIG. 8B may be disposed within the firstfree pattern130aofFIG. 8D. According to example embodiments of inventive concepts, theparticle180 ofFIG. 8B may be disposed in the secondfree pattern300a. According to example embodiments of inventive concepts, thethin pattern235a′ may be replaced with thethin pattern235aofFIG. 7.

Next, methods of manufacturing a magnetic memory device according to example embodiments of inventive concepts will be described with reference to the drawings.

FIGS. 9A and 9B are sectional views illustrating manufacturing methods of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 9A, a first electrodeconductive layer105, areference layer120, atunnel barrier layer125, and afree layer130 may be sequentially formed on a firstinterlayer dielectric layer102. Amaterial layer233 having an uneven thickness may be formed on thefree layer130. Thematerial layer233 may include a first portion and a second portion having a thinner thickness than the first portion. According to example embodiments of inventive concepts, thematerial layer233 may include a material for lowering wettability. The wettability refers to a degree thatmaterial layer233 spreads on thefree layer130. In example embodiments, the sum of the surface energy of thefree layer130 and the surface energy of thematerial layer233 may be less than an interfacial energy between thefree layer130 and thematerial layer233. Thereby, the wettability becomes lower such that thematerial layer233 may be formed with an uneven thickness. Alternatively, by changing the surface energy of thefree layer130 regardless of kinds of materials of thematerial layer233, the wettability of thematerial layer233 may be lowered. This will be described with reference to the drawings.

FIG. 9C is a flowchart illustrating a method of forming the material layer ofFIG. 9A.

Referring toFIGS. 9A and 9C, before the forming of thematerial layer233, the surface energy of thefree layer130 may be adjusted by irradiating an ion beam on the exposed surface of the free layer130 (S61). According to example embodiments of inventive concepts, the ion beam may be irradiated to decrease the surface energy of thefree layer130. Accordingly, the sum of the surface energy of thefree layer130 and the surface energy of thematerial layer233 may be decreased. Thematerial layer233 may be formed on the surface of afree layer130 on which an ion beam is irradiated (S62). Thematerial layer233 may be formed through a sputtering process. The wettability for thefree layer130 of thematerial layer233 may be lowered by adjusting the surface energy of the exposed surface of the free layer using the ion beam, such that thematerial layer233 may be formed with an uneven thickness. Thematerial layer233 may include a nonmagnetic metal. For example, thematerial layer233 may include at least one of tantalum, zinc, hafnium, zirconium, magnesium, titanium, chrome, or copper.

Referring toFIG. 9B, according to example embodiments of inventive concepts, athin layer235 and a surfacelocal region170 may be formed by oxidizing thematerial layer233 having an uneven thickness. Oxygen supplied for oxidation of thematerial layer233 may be supplied to a portion of the second surface of thefree layer130 through a relatively thin portion of thematerial layer233. Accordingly, thethin layer235 and the surfacelocal region170 may be formed simultaneously. In example embodiments, thethin layer235 may include an oxide formed by oxidizing thematerial layer233, and the surfacelocal region170 may include an oxide formed by oxidizing a portion of thefree layer130. Thematerial layer233 may be oxidized through a natural oxidation, a radical oxidation process or a plasma oxidation process.

Unlike this, thethin layer235 and the surfacelocal region170 may be formed by nitrifying thematerial layer233 having the uneven thickness. In example embodiments, the surfacelocal region170 may include a nitride formed by nitrifying a portion of thefree layer130, and thethin layer235 may include a nitride formed by nitrifying thematerial layer233. Thematerial layer233 may be nitrified through a radical nitrification process or a plasma nitrification process.

Next, thepassivation layer140 and the second electrodeconductive layer145 ofFIG. 3C may be sequentially formed on thethin layer235. Next, the second electrodeconductive layer145, thepassivation layer140, thethin layer235, thefree layer130, thetunnel barrier layer125, thereference layer120, and the first electrodeconductive layer105 are sequentially patterned to form thepatterns105a,120a,125a,130a,140a, and145aofFIG. 7. Next, by sequentially forming the secondinterlayer dielectric layer150, theupper contact plug152, and theinterconnection155, the magnetic memory device ofFIG. 7 may be realized.

Alternatively, thematerial layer233 may be formed to have a first portion of an amorphous state and a second portion of a crystalline state. In example embodiments, oxygen for oxidation or nitrogen for nitrification may be provided to thefree layer130 through the second portion of the crystalline state in thematerial layer233. In example embodiments, thematerial layer233 may be formed with a uniform thickness. Therefore, thethin layer235 ofFIG. 9B may be formed with a uniform thickness. Next, a passivation layer and a second electrode conductive layer may be sequentially formed, and stacked layers may be consecutively patterned. Therefore, the magnetic memory device ofFIG. 8A may be realized.

According to example embodiments of inventive concepts, theparticles180 may be formed in thefree layer130 ofFIG. 9A using one of the methods ofFIGS. 5A through 5C. The following processes may be equal to those ofFIG. 9B. Thereby, the magnetic memory device ofFIG. 8B may be realized.

According to example embodiments of inventive concepts, after the forming of the surfacelocal region170, the surfacelocal region170 and thefree layer130 may be exposed by removing thethin layer235 ofFIG. 9B. Next, a passivation layer and a second electrode conductive layer are sequentially formed and a patterning process may be performed. Therefore, the magnetic memory device ofFIG. 8C may be realized.

According to example embodiments of inventive concepts, a second free layer, a second tunnel barrier layer, a second reference layer, and a second electrode conductive layer are sequentially formed on a thin layer, and the stacked layers are consecutively patterned to form the MTJ pattern ofFIG. 8D. Later, a second interlayer dielectric layer, an upper contact plug, and interconnections may be sequentially formed. Therefore, the magnetic memory device ofFIG. 8D may be realized.

Throughout embodiments, like reference numerals refer to like elements and their overlapping description will be omitted.

FIG. 10A is a sectional view illustrating a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 10A, afirst electrode105a, areference pattern120a, atunnel barrier pattern125a, afree pattern130a, apassivation pattern140a, asecond electrode145amay be sequentially stacked on a firstinterlayer dielectric layer102. At least oneparticle280 may be disposed within thefree pattern130a. Theparticle280 may include a nonmagnetic conductive material. Theparticle280 may be spaced from the bottom and top surfaces of thefree pattern130a. For example, theparticles280 may include at least one of tantalum, zinc, hafnium, zirconium, magnesium, titanium, chrome, copper, a tantalum nitride, a zinc nitride, a hafnium nitride, a zirconium nitride, a magnesium nitride, a titanium nitride, a chrome nitride, or a copper nitride. According to example embodiments of inventive concepts, thefree pattern130amay contact thepassivation pattern140a.

Theparticle280 may include a different material from thefree pattern130a, such that atomic-magnetic moments non-parallel to the top and bottom surfaces of thefree pattern130amay be generated in a portion of thefree pattern130aaround theparticle280. Thereby, a critical current density for reversing the magnetization direction of thefree pattern130amay be reduced. As a result, a magnetic memory device improved or optimized for lower power consumption and/or higher degree of integration may be realized. Theparticle280 includes a nonmagnetic conductive material, such that resistance increase of thefree pattern130amay be reduced or minimized. Accordingly, a magnetic resistance ratio of the MTJ pattern may be minimally reduced, such that a magnetic memory device with excellent reliability may be realized.

FIG. 10B is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 10B, according to this modification, afirst electrode105a, apassivation pattern140a, afree pattern130aincluding aparticle280, atunnel barrier pattern125a, areference pattern120a, and asecond electrode145amay be sequentially stacked on a firstinterlayer dielectric layer102. According to this modification, thefree pattern130ais disposed below thetunnel barrier pattern125aand thereference pattern120amay be disposed on thetunnel barrier pattern125a. Thepassivation pattern140amay be omitted.

FIG. 10C is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts. The above-mentionedreference pattern120aandtunnel barrier pattern125amay correspond to afirst reference pattern120aand a firsttunnel barrier pattern125a, respectively.

Referring toFIG. 10C, according to this modification, an MTJ pattern may include thefirst reference pattern120a, the firsttunnel barrier pattern125a, thefree pattern130a, a secondtunnel barrier pattern305a, and asecond reference pattern315a, which are sequentially stacked on a firstinterlayer dielectric layer102. Moreover, the MTJ pattern may further include aparticle280 within thefree pattern130a. Afirst electrode105amay be disposed between thefirst reference pattern120aand the firstinterlayer dielectric layer102, and thesecond electrode145amay be disposed on thesecond reference pattern315a.

According to this modification, the first and secondtunnel barrier patterns125aand305amay contact the bottom and top surfaces of thefree pattern130a, respectively. In the modification, as shown in the drawings, the fixed magnetization direction of the second pinnedpattern116aof thefirst reference pattern120amay be anti-parallel to that of the second pinnedpattern307aof thesecond reference pattern315a. An anti-ferromagnetic material in the pinningpattern110aof thefirst reference pattern120amay have a first blocking temperature, and an anti-ferromagnetic material in the pinningpattern313aof thesecond reference pattern315amay have a second blocking temperature. The first blocking temperature may be different from the second blocking temperature. Therefore, after heat with a temperature between the first and second blocking temperatures is applied to the MTJ pattern, an external magnetic field is provided to arrange the magnetization directions of the second pinnedpatterns116aand313aof the first andsecond reference patterns120aand315ato be anti-parallel to each other. For example, one of the pinningpatterns116aand313aof the first andsecond reference patterns120aand315amay include IrMn and the other may include PtMn.

When electrons in a program current flow from thefirst electrode105ato thesecond electrode145a, first electrons penetrating the second pinnedpattern116aof thefirst reference pattern120amay be accumulated in thefree pattern130a. In addition, second electrons reflected by the second pinnedpattern307aof thesecond reference pattern315amay be accumulated in thefree pattern130a. The electrons may have spins parallel to the magnetization direction of the second pinnedpattern116a, and the second electrons may have spins anti-parallel to the magnetization direction of the second pinnedpattern307a. That is, the spins of the first electrons are parallel to that of the second electrons. Therefore, a magnetization direction of thefree pattern130acan be reversed. As a result, a critical current density is reduced by theparticle280 along with thereference patterns120aand315aand thefree pattern130a. Therefore, a magnetic memory device having lower power consumption and/or higher degree of integration may be realized.

FIG. 11A is a sectional view illustrating a method of manufacturing a magnetic memory device according to example embodiments of inventive concepts.FIG. 11B is a flowchart illustrating a method of forming the free layer ofFIG. 11A.FIG. 11C is a flowchart illustrating another method of forming the free layer ofFIG. 11A.

Referring toFIG. 11A, a first electrodeconductive layer105, areference layer120, and atunnel barrier layer125 are sequentially formed on a firstinterlayer dielectric layer102, and afree layer130 including aparticle280 may be formed on thetunnel barrier layer125. A method of forming thefree layer130 including theparticle280 will be described with reference toFIG. 11B.

Referring toFIGS. 11A and 11B, a first sub magnetic layer is formed on the tunnel barrier layer125 (S71). Aparticle280 including a nonmagnetic conductive material is formed on the first sub magnetic layer (S72), and a second sub magnetic layer is formed on the first sub magnetic layer and the particle280 (S73). The first and second sub magnetic layers may be included in thefree layer130. The first and second sub magnetic layers may be formed of the same magnetic material. Therefore, thefree layer130 including theparticle280 may be formed.

Another method of forming thefree layer130 including theparticle280 will be described with reference toFIG. 11C.

Referring toFIGS. 11A and 11C, an alloy including a magnetic material and a nonmagnetic conductive material may be prepared (S81). A content ratio of the magnetic material in the alloy may be far greater than that of the nonmagnetic conductive material in the alloy. By performing a sputtering process using the alloy as a target, afree layer130 including theparticle280 may be formed (S82). During the sputtering process, the nonmagnetic conductive material of a relatively small amount may be segmented in the magnetic material, such that theparticle280 may be formed.

According to example embodiments of inventive concepts, a first electrodeconductive layer105, apassivation layer140, afree layer130 including aparticle280, atunnel barrier layer125, areference layer120, and a second electrodeconductive layer145 may be sequentially formed on a firstinterlayer dielectric layer102. Then, by performing subsequent processes including a process for patterning the stacked layers, the magnetic memory device ofFIG. 10B may be realized.

According to example embodiments of inventive concepts, as shown inFIG. 11A, a process for forming a passivation layer is omitted, and before the forming of the second electrode layer, the secondtunnel barrier layer305 ofFIG. 6C and thesecond reference layer315 ofFIG. 6C may be sequentially formed on the top surface of thefree layer130. Later, by performing subsequent processes including a process for consecutively patterning the stacked layers, the magnetic memory device ofFIG. 10C may be realized.

Throughout example embodiments, like reference numerals refer to like elements and their overlapping description will be omitted.

FIG. 12 is a sectional view illustrating a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 12, afirst electrode405, areference pattern420, atunnel barrier pattern425, afree pattern430, a perpendicular anisotropy enhancedpattern435, apassivation pattern140a, and asecond electrode145amay be sequentially stacked on a firstinterlayer dielectric layer102. Thefree pattern430 has a first surface adjacent to thetunnel barrier pattern425 and a second surface contacting the perpendicular anisotropy enhancedpattern435. The first and second surfaces of thefree pattern430 may correspond to the bottom and top surfaces of thefree pattern430, respectively. The first and second surfaces of thefree pattern430 may be opposite to each other and may be parallel to each other. In addition, the first and second surfaces of thefree pattern430 may be parallel to the top surface of thesubstrate100.

Thereference pattern420 may include a reference perpendicularmagnetic pattern410 and aspin polarization pattern415 disposed between the reference perpendicularmagnetic pattern410 and thetunnel barrier pattern425. According to example embodiments of inventive concepts, thespin polarization pattern415 may contact the reference perpendicularmagnetic pattern410 and thetunnel barrier pattern425. The reference perpendicularmagnetic pattern410 may have a first fixed magnetization direction substantially perpendicular to the first and second surfaces of thefree pattern430. Thespin polarization pattern415 may have a second fixed magnetization direction substantially perpendicular to the first and second surfaces of thefree pattern430.

The reference perpendicularmagnetic pattern410 may have a material and/or a structure having the first fixed magnetization direction by itself. For example, the reference perpendicularmagnetic pattern410 may include at least one of a perpendicular magnetic material (e.g., CoFeTb, CoFeGd, or CoFeDy and so on), a perpendicular magnetic material of an L10 structure, CoPt of a hexagonal close packed lattice structure, or an alloy thereof. The perpendicular magnetic material of an L10 structure may include at least one of FePt of an L1₀structure, FePd of an L1₀structure, CoPd of an L1₀structure, or CoPt of an L1₀structure. When the reference perpendicularmagnetic pattern410 includes CoFeTb, a Tb content ratio in CoFeTb may be equal to or more than about 10%. Similarly, when the reference perpendicularmagnetic pattern410 includes CoFeGd, a Gd content ratio in CoFeGb may be equal to or more than about 10%. According to example embodiments of inventive concepts, the reference perpendicularmagnetic pattern410 may include a perpendicular magnetic structure having magnetic layers and nonmagnetic layers, which are alternately and repeatedly stacked. For example, the perpendicular magnetic structure may include at least one of (Co/Pt)n, (CoFe/Pt)n, (CoFe/Pd)n, (CoP)n, (Co/Ni)n, (CoNi/Pt)n, (CoCr/Pt)n, or (CoCr/Pd)n (n is the number of stacked layers).

Thefirst electrode405 may perform a function of a seed layer about the reference perpendicularmagnetic pattern410. Furthermore, thefirst electrode405 may include a conductive material having an excellent barrier property. For example, when the reference perpendicularmagnetic pattern410 includes a perpendicular magnetic material of an L1₀structure, thefirst electrode405 may include a conductive metal nitride having a sodium chloride structure (e.g., a titanium nitride, a tantalum nitride, a chrome nitride, or a vanadium nitride). However, inventive concepts are not limited thereto. Thefirst electrode405 may include another conductive material.

Thespin polarization pattern415 may include a magnetic material. The second fixed magnetization direction of thespin polarization pattern415 may be fixed substantially perpendicular to the first and second surfaces of thefree pattern430 by the reference perpendicularmagnetic pattern410. According to example embodiments of inventive concepts, when thespin polarization pattern415 contacts the reference perpendicularmagnetic pattern410, the second fixed magnetization direction of thespin polarization pattern415 may be parallel to the first fixed magnetization direction of the reference perpendicularmagnetic pattern410. For example, thespin polarization pattern415 may include at least one of CoFeB, CoFe, NiFe, CoFePt, CoFePd, CoFeCr, CoFeTb, CoFeGd, or CoFeNi. When thespin polarization pattern415 includes iron (Fe) and cobalt (Co), a content ratio of iron (Fe) in thespin polarization pattern415 may be greater than a content ratio of cobalt (Co) in thespin polarization pattern415. Therefore, the second fixed magnetization direction of thespin polarization pattern415 may become easily perpendicular to the first and second surfaces of thefree pattern430.

Thetunnel barrier pattern425 may have a thickness that is less than a spin diffusion length. Thetunnel barrier pattern425 may include an insulating material. For example, thetunnel barrier pattern425 may include at least one of a magnesium oxide, a titanium oxide, an aluminum oxide, a magnesium-zinc oxide, or a magnesium-boron oxide.

Thefree pattern430 may include a magnetic material. For example, thefree pattern430 may include at least one of CoFeB, CoFe, NiFe, CoFePt, CoFePd, CoFeCr, CoFeTb, CoFeGd, or CoFeNi. When thefree pattern430 includes CoFeTb, a Tb content ratio in CoFeTb of thefree pattern430 may be equal to or more than about 10%. Similarly, when thefree pattern430 includes CoFeGd, a Gd content ratio in CoFeGb of thefree pattern430 may be equal to or more than about 10%.

The perpendicular anisotropy enhancedpattern435 may contact the second surface (e.g., the top surface) of thefree pattern430, such that atomic-magnetic moments perpendicular to the second surface of thefree pattern430 are generated in thefree pattern430. Accordingly, the magnetization direction of thefree pattern430 may be substantially perpendicular to the second surface of thefree pattern430. In example embodiments, a net magnetization direction by the vector sum of the atomic-magnetic moments in thefree pattern430 may be substantially perpendicular to the second surface of thefree pattern430. The perpendicular anisotropy enhancedpattern435 may apply stress (compressive force or tensile force) to thefree pattern430. Accordingly, the atomic-magnetic moments perpendicular to the second surface may be generated in thefree pattern430, such that thefree pattern430 may have a magnetization direction that is substantially perpendicular to the second surface of thefree pattern430. According to example embodiments of inventive concepts, if the perpendicular anisotropy enhancedpattern435 does not contact thefree pattern430, thefree pattern430 may have the atomic-magnetic moments non-perpendicular to the second surface of thefree pattern430. The non-perpendicular atomic-magnetic moments may be converted to be perpendicular to the second surface by the perpendicular anisotropy enhancedpattern435.

The perpendicular magnetization direction of thefree pattern430 may be changeable to parallel or anti-parallel to the fixed magnetization direction of the reference pattern420 (e.g., the second fixed magnetization direction of the spin polarization pattern415). The perpendicular magnetization direction of thefree pattern430 may be changed by spins of electrons in a program current.

According to example embodiments of inventive concepts, thefree pattern430 may include iron (Fe) and (Co). A content ratio of iron (Fe) in thefree pattern430 may be greater than a content ratio of cobalt (Co) in thefree pattern430, such that a perpendicular anisotropy characteristic of thefree pattern430 may be further improved. According to example embodiments of inventive concepts, thefree pattern430 may have a thin thickness to have the perpendicular magnetization direction. For example, thefree pattern430 may have a thickness of about 10 Å to about 20 Å. However, inventive concepts are not limited thereto. Thefree pattern430 may have various thicknesses.

The perpendicular anisotropy enhancedpattern435 may have a nonmagnetic metal compound. For example, the perpendicular anisotropy enhancedpattern435 may include a nonmagnetic metal oxide. A content ratio of a nonmagnetic metal in the nonmagnetic metal oxide of the perpendicular anisotropy enhancedpattern435 may be greater than a stoichiometric ratio. That is, the perpendicular anisotropy enhancedpattern435 may include a nonmagnetic metal-rich metal oxide. Accordingly, a resistivity of the perpendicular anisotropy enhancedpattern435 can be reduced such that magnetic resistivity reduction by the perpendicular anisotropy enhancedpattern435 may be reduced or minimized. According to example embodiments of inventive concepts, a concentration of the nonmagnetic metal in the perpendicular anisotropy enhancedpattern435 may be substantially uniform over the entire perpendicular anisotropy enhancedpattern435. Accordingly, a resistivity of the perpendicular anisotropy enhancedpattern435 may be substantially uniformly reduced. For example, the perpendicular anisotropy enhancedpattern435 may include at least one of a hafnium-rich hafnium oxide, a tantalum-rich tantalum oxide, a zirconium-rich oxide, a chromium-rich chromium oxide, a vanadium-rich vanadium oxide, a molybdenum-rich molybdenum oxide, a titanium-rich titanium oxide, a tungsten-rich tungsten oxide, an yttrium-rich yttrium oxide, a magnesium-rich magnesium oxide, or a zinc-rich zinc oxide. According to example embodiments of inventive concepts, the perpendicular anisotropy enhancedpattern435 may include a tantalum-rich tantalum oxide.

According to example embodiments of inventive concepts, a nonmagnetic metal compound of the perpendicular anisotropy enhancedpattern435 may include a non-magnetic metal nitride. For example, the perpendicular anisotropy enhancedpattern435 may include at least one of a hafnium nitride, a tantalum nitride, a zirconium nitride, a chrome nitride, a vanadium nitride, a molybdenum nitride, a titanium nitride, a tungsten nitride, an yttrium nitride, a magnesium nitride, or a zinc nitride. According to example embodiments of inventive concepts, a content ratio of a nonmagnetic metal in the nonmagnetic metal nitride may be greater than a stoichiometric ratio.

As shown inFIG. 12, apassivation pattern140aand asecond electrode145amay be sequentially stacked on the perpendicular anisotropy enhancedpattern435, and a secondinterlayer dielectric layer150 may cover the front surface of asubstrate100. Components with the same reference numerals described with the above-mentioned example embodiments will not be described.

In relation to the magnetic memory device according to the above-mentioned example embodiments, thefree pattern430 may have a magnetization direction perpendicular to the second surface (e.g., the top surface of the free pattern430) of thefree pattern430 by the perpendicular anisotropy enhancedpattern435. Accordingly, thefree pattern430 may itself not include a perpendicular magnetic material and/or a perpendicular magnetic structure having a perpendicular magnetization. Therefore, a perpendicular magnetic memory device having a very simple structure may be realized, and also a process margin of a method of manufacturing the perpendicular magnetic memory device may be improved. As a result, a perpendicular magnetic memory device having improved or excellent reliability and improved or optimized for a higher degree of integration may be realized. Moreover, since thefree pattern430 may have the perpendicular magnetization direction by the perpendicular anisotropy enhancedpattern435, the thickness of thefree pattern430 may be reduced. Accordingly, a critical current amount required for changing a magnetization direction of thefree pattern430 may be reduced. As a result, a perpendicular magnetic memory device improved or optimized for lower power consumption and/or higher degree of integration may be realized by reducing a program current amount.

A method of a program operation in the magnetic memory device ofFIG. 12 will be described. When the magnetization direction of thefree pattern430 is anti-parallel to the first fixed magnetization direction of thespin polarization pattern415, electrons in a program current may flow from thereference pattern420 to thefree pattern430. Major electrons parallel to the first fixed magnetization direction of thespin polarization pattern415 may be accumulated in thefree pattern430. The magnetization direction of thefree pattern430 may be changed to be parallel to thereference pattern420 by spin torques of the major electrons accumulated in thefree pattern430.

In contrast, when the magnetization directions of thefree pattern430 and thespin polarization pattern415 are parallel to each other, electrons in a program current may flow from thefree pattern430 to thereference pattern420. Minor electrons anti-parallel to the magnetization direction of thespin polarization pattern415 are reflected by thespin polarization pattern415 and then are accumulated in thefree pattern430. Thefree pattern430 may be reversed to be anti-parallel to thespin polarization pattern415 by the minor electrons accumulated in thefree pattern430.

Next, modifications of the magnetic memory device according to example embodiments will be described with reference to the drawings. In the following modifications, like reference numerals refer to like elements.

FIG. 13A is a sectional view illustrating a modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 13A, according to this modification, apassivation pattern140a, a perpendicular anisotropy enhancedpattern435, afree pattern430, atunnel barrier pattern425, areference pattern420, and asecond electrode145amay be sequentially stacked on thefirst electrode405. That is, according to this modification, thefree pattern430 may be disposed below thetunnel barrier pattern425, and thereference pattern420 may be disposed on thetunnel barrier pattern425. In example embodiments, the first surface of thefree pattern430, adjacent to thetunnel barrier pattern425, and the second surface of thefree pattern430, contacting the perpendicular anisotropy enhancedpattern435, may correspond to a top surface and a bottom surface of thefree pattern430, respectively.

The reference perpendicularmagnetic pattern410 of thereference pattern420 may be disposed on thetunnel barrier pattern425, and thespin polarization pattern415 of thereference pattern420 may be disposed between the top surface of thetunnel barrier pattern425 and thereference pattern420. According to example embodiments of inventive concepts, the bottom surface of thetunnel barrier pattern425 may contact thefree pattern430, and the top surface of thetunnel barrier pattern425 may contact thespin polarization pattern415. In this modification,passivation pattern140amay be omitted. In example embodiments, the perpendicular anisotropy enhancedpattern435 may be disposed directly on thefirst electrode405.

FIG. 13B is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 13B, according to this modification, a fixed perpendicularmagnetic pattern450 may be disposed on one surface of the perpendicular anisotropy enhancedpattern435. The perpendicular anisotropy enhancedpattern435 may be disposed between the fixed perpendicularmagnetic pattern450 and thefree pattern430. According to this modification, thereference pattern420, thetunnel barrier pattern425, thefree pattern430, the perpendicular anisotropy enhancedpattern435, the fixed perpendicularmagnetic pattern450, thepassivation pattern140a, and/or thesecond electrode145amay be sequentially stacked on thefirst electrode405.

The fixed perpendicularmagnetic pattern450 may have a fixed magnetization direction being substantially perpendicular to the top surface of thefree pattern430. According to this modification, thereference pattern420 may correspond to a first reference pattern, and the fixed perpendicularmagnetic pattern450 may correspond to a second reference pattern. According to example embodiments of inventive concepts, the fixed perpendicularmagnetic pattern450 may be anti-parallel to the fixed magnetization direction (especially, the fixed magnetization direction of thespin polarization pattern415 adjacent to the tunnel barrier pattern425) of thereference pattern420.

The fixed perpendicularmagnetic pattern450 by itself may have a perpendicular magnetization direction. For example, the fixed perpendicularmagnetic pattern450 includes at least one of a perpendicular magnetic material (e.g., CoFeTb, CoFeGd, or CoFeDy and so on), a perpendicular magnetic material of an L10 structure, CoPt of a hexagonal close packed lattice structure, or an alloy thereof. The perpendicular magnetic material of an L10 structure may include at least one of FePt of an L1₀structure, FePd of an L1₀structure, CoPd of an L1₀structure, or CoPt of an L1₀structure. When the fixed perpendicularmagnetic pattern450 includes CoFeTb, a Tb content ratio in CoFeTb may be equal to or more than about 10%. Similarly, when the fixed perpendicularmagnetic pattern450 includes CoFeGd, a Gd content ratio in CoFeGb may be equal to or more than about 10%. According to example embodiments of inventive concepts, the fixed perpendicularmagnetic pattern450 may include a perpendicular magnetic structure having magnetic layers and nonmagnetic layers, which are alternately and repeatedly stacked. For example, the perpendicular magnetic structure may include at least one of (Co/Pt)n, (CoFe/Pt)n, (CoFe/Pd)n, (CoP)n, (Co/Ni)n, (CoNi/Pt)n, (CoCr/Pt)n, or (CoCr/Pd)n (n is the number of stacked layers).

When the magnetization direction of thefree pattern430 is anti-parallel to that of thespin polarization pattern415, electrons in a program current may flow from thereference pattern420 to thefree pattern430. First electrons penetrating thespin polarization pattern415 and having spins parallel to the magnetization direction of thespin polarization pattern415 may be accumulated in thefree pattern430. In addition, second electrons reflected by the magnetization direction of the fixed perpendicularmagnetic pattern450 and having spins anti-parallel to the magnetization direction of the fixed perpendicularmagnetic pattern450 may be accumulated in thefree pattern430. The spin directions of the second electrons are parallel to those of the first electrons. By spin torques of the first and second electrons accumulated in thefree pattern430, the magnetization direction of thefree pattern430 is reversed, such that it may be parallel to the magnetization direction of thespin polarization pattern415. The first and second electrons are accumulated in thefree pattern430 such that a critical current density for reversing thefree pattern430 may be reduced.

When the magnetization direction of thefree pattern430 is parallel to that of thespin polarization pattern415, electrons in a program current may flow from the fixed perpendicularmagnetic pattern450 to thereference pattern420. Electrons penetrating the fixed perpendicularmagnetic pattern450 and having spins parallel to the magnetization direction of the fixed perpendicularmagnetic pattern450 may be accumulated in thefree pattern430. In addition, electrons reflected by the magnetization direction of thespin polarization pattern415 and anti-parallel to the magnetization direction of thespin polarization pattern415 may be accumulated in thefree pattern430. Due to this, the magnetization direction of thefree pattern430 is reversed to be anti-parallel to the magnetization direction of thespin polarization pattern415.

According to example embodiments, similar to the magnetic memory device ofFIG. 13A, thefree pattern430 and the fixed perpendicularmagnetic pattern450 ofFIG. 13B may be disposed below thetunnel barrier pattern425, and thereference pattern420 may be disposed on thetunnel barrier pattern425. In example embodiments, thepassivation pattern140a, the fixed perpendicularmagnetic pattern450, the perpendicular anisotropy enhancedpattern435, thefree pattern430, thetunnel barrier pattern425, thespin polarization pattern415, the reference perpendicularmagnetic pattern410, and/or thesecond electrode145amay be sequentially stacked on thefirst electrode405. In example embodiments, thepassivation pattern140amay be omitted.

FIG. 13C is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 13C, according to this modification, areference pattern420amay include the reference perpendicularmagnetic pattern410, thespin polarization pattern415, and anexchange coupling pattern412 disposed therebetween. According to this modification, theexchange coupling pattern412 may combine the magnetization direction of the reference perpendicularmagnetic pattern410 and the magnetization direction of thespin polarization pattern415 to be parallel to each other. By theexchange coupling pattern412, a parallel combination between the magnetization directions of the reference perpendicularmagnetic pattern410 and thespin polarization pattern415 may be enhanced. According to this modification, theexchange coupling pattern412 may include at least one of nonmagnetic metals such as titanium, tantalum, or magnesium, an oxide thereof, or a nitride thereof.

According to example embodiments of inventive concepts, the fixed perpendicularmagnetic pattern450 may be omitted from the magnetic memory device ofFIG. 13C.

According to example embodiments of inventive concepts, the perpendicular anisotropy enhancedpattern435 and thefree pattern430 may be disposed below thetunnel barrier pattern425 in the magnetic memory device ofFIG. 13C. In example embodiments, thepassivation pattern140a, the fixed perpendicularmagnetic pattern450, the perpendicular anisotropy enhancedpattern435, thefree pattern430, thetunnel barrier pattern425, thespin polarization pattern415, theexchange coupling pattern412, the reference perpendicularmagnetic pattern410, and/or thesecond electrode145amay be sequentially stacked on thefirst electrode405. In example embodiments, thepassivation pattern140aand/or the fixed perpendicularmagnetic pattern450 may be omitted.

FIG. 13D is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 13D, according to this modification, anexchange coupling pattern412aincluded in areference pattern420bmay combine the magnetization directions of thespin polarization pattern415 and the reference perpendicularmagnetic pattern410 to be anti-parallel to each other. Accordingly, a magnetic stray field by thereference pattern420bmay be reduced or minimized such that reliability of the magnetic memory device may be improved. For example, theexchange coupling pattern412amay include at least one rare metal such as Ru, Ir, or Rh. In the modification, the magnetization direction of the fixed perpendicularmagnetic pattern450 may be anti-parallel to that of thespin polarization pattern415.

According to example embodiments of inventive concepts, the fixed perpendicularmagnetic pattern450 may be omitted from the magnetic memory device ofFIG. 13D.

According to example embodiments of inventive concepts, the perpendicular anisotropy enhancedpattern435 and thefree pattern430 may be disposed below thetunnel barrier pattern425 in the magnetic memory device ofFIG. 13D. In example embodiments, thepassivation pattern140a, the fixed perpendicularmagnetic pattern450, the perpendicular anisotropy enhancedpattern435, thefree pattern430, thetunnel barrier pattern425, thespin polarization pattern415, theexchange coupling pattern412a, the reference perpendicularmagnetic pattern410, and/or thesecond electrode145amay be sequentially stacked on thefirst electrode405. In example embodiments, thepassivation pattern140aand/or the fixed perpendicularmagnetic pattern450 may be omitted.

FIG. 13E is a sectional view illustrating another modification of a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 13E, a free perpendicularmagnetic pattern470 may be disposed on one surface of the perpendicular anisotropy enhancedpattern435. The perpendicular anisotropy enhancedpattern435 may be disposed between thefree pattern430 and the free perpendicularmagnetic pattern470. For example, thereference pattern420a, thetunnel barrier pattern425, thefree pattern430, the perpendicular anisotropy enhancedpattern435, the free perpendicularmagnetic pattern470, thepassivation pattern140a, and/or thesecond electrode145amay be sequentially stacked on thefirst electrode405. The free perpendicularmagnetic pattern470 may have a magnetization direction that is substantially perpendicular to the top and bottom surfaces of thefree pattern430. The magnetization direction of the free perpendicularmagnetic pattern470 may be changeable to be parallel or anti-parallel the fixed magnetization direction (for example, the magnetization direction of the spin polarization pattern415) of thereference pattern420a. The magnetization direction of the free perpendicularmagnetic pattern470 may be parallel to that of thefree pattern430. The magnetization direction of the free perpendicularmagnetic pattern470 and the magnetization direction of thefree pattern430 may be all changeable. The free perpendicularmagnetic pattern470 and thefree pattern430 may be included in a data storage element. Due to the free perpendicularmagnetic pattern470, data retention of a unit cell of the magnetic memory device may be improved.

The free perpendicularmagnetic pattern470 by itself may have a perpendicular magnetization direction. For example, free perpendicularmagnetic pattern470 may include at least one of a perpendicular magnetic material (e.g., CoFeTb, CoFeGd, or CoFeDy and so on), a perpendicular magnetic material of an L10 structure, CoPt of a hexagonal close packed lattice structure, or an alloy thereof. The perpendicular magnetic material of an L10 structure may include at least one of FePt of an L1₀structure, FePd of an L1₀structure, CoPd of an L1₀structure, or CoPt of an L1₀structure. When the free perpendicularmagnetic pattern470 includes CoFeTb, a Tb content ratio in CoFeTb may be equal to or more than about 10%. Similarly, when the free perpendicularmagnetic pattern470 includes CoFeGd, a Gd content ratio in CoFeGb may be equal to or more than about 10%. According to example embodiments of inventive concepts, the free perpendicularmagnetic pattern470 may include a perpendicular magnetic structure having magnetic layers and nonmagnetic layers, which are alternately and repeatedly stacked. For example, the perpendicular magnetic structure may include at least one of (Co/Pt)n, (CoFe/Pt)n, (CoFe/Pd)n, (CoP)n, (Co/Ni)n, (CoNi/Pt)n, (CoCr/Pt)n, or (CoCr/Pd)n (n is the number of stacked layers).

The free perpendicularmagnetic pattern470 may have a first critical current amount, and the reference perpendicularmagnetic pattern410 may have a second critical current amount. The first critical current amount may mean a current amount required to change the magnetization direction of the free perpendicularmagnetic pattern470, and the second critical current amount may mean a current amount required to change the magnetization direction of the reference perpendicularmagnetic pattern410. In example embodiments where the first critical current amount may be less than the second critical current amount, a program current amount may be greater than the first critical current amount and less than the second critical current amount. Accordingly, the magnetization direction of the free perpendicularmagnetic pattern470 may be changeable but the magnetization direction of the reference perpendicularmagnetic pattern410 may be fixed. The first and second critical current amounts may be determined by various factors. For example, in order for the first critical current amount to be less than the second critical current amount, the thickness of the free perpendicularmagnetic pattern470 may be thinner than that of the reference perpendicularmagnetic pattern410. Or, coercive force of the free perpendicularmagnetic pattern470 may be less than that of the reference perpendicularmagnetic pattern410.

According to example embodiments of inventive concepts, thereference pattern420amay be replaced with thereference pattern420bofFIG. 13D in the magnetic memory device ofFIG. 13E.

According to example embodiments of inventive concepts, thepassivation pattern140a, the free perpendicularmagnetic pattern470, the perpendicular anisotropy enhancedpattern435, thefree pattern430, thetunnel barrier pattern425, thereference pattern420a, and/or thesecond electrode145amay be sequentially stacked on thefirst electrode405. In example embodiments, thespin polarization pattern415 of thereference pattern420amay be disposed right on thetunnel barrier pattern425. In example embodiments, thereference pattern420amay be replaced with thereference pattern420bofFIG. 13D. Thepassivation pattern140amay be omitted.

The magnetic memory devices according to the above-mentioned example embodiments may be realized through semiconductor packages of various forms. For example, the magnetic memory devices according to embodiments of inventive concepts may be packaged through various package methods such as Package on Package (PoP), Ball Grid Arrays (BGA), Chip Scale Packages (CSP), Plastic Leaded Chip Carrier (PLCC), Plastic Dual In-line Package (PDIP), Die in Waffle Pack, Die in Wafer Form, Chip On Board (COB), Ceramic Dual In-line Package (CERDIP), Plastic Metric Quad Flat Pack (MQFP), Thin Quad Flat Pack (TQFP), Small Outline Integrated Circuit (SOIC), Shrink Small Outline Package (SSOP), Thin Small Outline Package (TSOP), System In Package (SIP), Multi Chip Package (MCP), Wafer-level Fabricated Package (WFP), and Wafer-level Processed Stack Package (WSP). Packages having a magnetic memory device according to example embodiments of inventive concepts may further include controller for controlling the magnetic memory device and/or logic devices.

FIG. 14 is a block diagram illustrating an electronic system including a magnetic memory device according to example embodiments of inventive concepts.

Referring toFIG. 14, theelectronic system1100 may include acontroller1110, an input/output device (or I/O)1120, amemory device1130, aninterface1140, and abus1150. Thecontroller1110, the input/output device1120, thememory device1130 and/or theinterface1140 may be connected through thebus1150. Thebus1150 corresponds to a path through which data may be transferred.

Thecontroller1110 may include at least one of microprocessors, digital signal processors, microcontrollers, and logic devices for performing similar functions thereof. The input/output device1120 may include a keypad, a keyboard, and a display device. Thememory device1130 may store data and/or commands. Thememory device1130 may include at least one of the magnetic memory devices described in the above-mentioned embodiments. Moreover, thememory device1130 may further include semiconductor memory devices of different forms (e.g., flash memory devices, phase change memory devices, DRAM devices and/or SRAM devices). Theinterface1140 transmits data to a communication network or receives data from the communication network. Theinterface1140 may be in a wired or wireless form. For example, theinterface1140 may include an antenna or a wired/wireless transceiver. Although not illustrated in the drawings, theelectronic system1100 may be an operating memory device for improving an operation of thecontroller1110 and may further include a high-speed DRAM device and/or SRAM device.

Theelectronic system1100 may be applied to a personal digital assistant (PDA), a portable computer, a web tablet, a wireless phone, a mobile phone, a digital music player, a memory card, and any electronic products for transmitting and receiving information in a wireless environment.

FIG. 15 is a block diagram illustrating a memory card including a magnetic memory device based on example embodiments of inventive concepts.

Referring toFIG. 15, thememory card1200 according to example embodiments of inventive concepts includes amemory device1210. Thememory device1210 may include at least one of magnetic memory devices described in the above-mentioned example embodiments. Additionally, thememory device1210 may further include semiconductor memory devices of different forms (e.g., flash memory devices, phase change memory devices, DRAM devices and/or SRAM devices). Thememory card1200 may include amemory controller1220 for controlling data exchange between a host and thememory device1210.

Thememory controller1220 may include aprocessing unit1222 for controlling general operations of a memory card. Moreover, thememory controller1220 may include aSRAM1221 used as an operating memory of theprocessing unit1222. Furthermore, thememory controller1220 may further include ahost interface1223 and amemory interface1225. Thehost interface1223 may include a data exchange protocol between thememory card1200 and a host. Thememory interface1225 may connect thememory controller1220 with thememory device1210. Furthermore, thememory controller1220 may further include an error correction code (ECC)block1224. TheECC block1224 may detect and correct errors of data read from thememory device1210. Although not illustrated in the drawings, thememory card1200 may further include a ROM device for storing code data to interface with a host. Thememory card1200 may be used as portable data storage card. Alternatively, thememory card1200 may be realized with a solid state disk (SSD) that may replace a hard disk of a computer system.

As discussed above, example embodiments of inventive concepts disclose the use of a non-magnetic non-parallel magnetism generator to increase the magnetization of a free pattern, for example of an MTJ, in a direction non-parallel to a major (for example, first or second) surface of the free pattern. In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator may include the nonmagnetic metal-oxide patterns135a,135a′, the surfacelocal regions160,170, theparticles180,280, thethin patterns235a,235a′, the perpendicular anisotropy enhancedpattern435, or any combination thereof. In example embodiments of inventive concepts, the non-magnetic non-parallel magnetism generator may increase the magnetization of a free pattern, for example of an MTJ, in a direction perpendicular to the major surface of the free pattern. In example embodiments of inventive concepts, the free pattern may be an inplane free layer or a perpendicular free pattern.

In a broader sense, example embodiments of inventive concepts are directed to methods of increasing the perpendicularity of a perpendicular free pattern. For example as shown inFIG. 16, example embodiments of inventive concepts are directed to a method of forming a magnetic tunneling junction S1600, which may further include forming a free pattern, forming a reference pattern, and forming a tunnel barrier pattern as discussed above (as well as forming any number of other patterns) and forming a non-magnetic non-parallel magnetism generator contacting thefree pattern1602.

In an even broader sense, example embodiments of inventive concepts are directed to methods of controlling the parameters of a method of manufacturing a magnetic memory device to produce an inplane free pattern or a perpendicular free pattern, depending on which is desired. For example as shown inFIG. 17, example embodiments of inventive concepts are directed to a method of forming a magnetic tunneling junction S1700, which may further include forming a free pattern, forming a reference pattern, and forming a tunnel barrier pattern as discussed above (as well as forming any number of other patterns) and controlling at least one parameter of at least one layer to increase a portion of the non-parallel magnetization of the free pattern of the MTJ.

In example embodiments of inventive concepts, for example, at least one of the thickness and the material of at least one of thefree pattern130a, the non-magneticnon-parallel magnetism generator135a, and thepassivation pattern140aofFIG. 1A, may be controlled to convert a portion of the magnetization of the free pattern from a direction parallel to a major surface of the free pattern, to the direction non-parallel to the major surface of the free pattern.

In example embodiments of inventive concepts, such a method may also include converting an inplane free pattern to a perpendicular free pattern, which allows for the simpler process of forming an inplane free pattern to be implemented, while still achieving the benefits of a perpendicular free pattern.

According to example embodiments of inventive concepts, by reducing or minimizing a critical switching current density, a magnetic memory device of lower power consumption may be realized. Additionally, a magnetic memory device improved or optimized for higher degree of integration and reducing or minimizing sizes of switching devices that control a critical switching current may be realized.

The above-disclosed subject matter is to be considered illustrative and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other example embodiments, which fall within the true spirit and scope of inventive concepts. Thus, to the maximum extent allowed by law, the scope of inventive concepts is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Claims (9)

What is claimed is:

1. A magnetic memory device comprising:

a reference pattern on a substrate;

a free pattern on the substrate;

a tunnel barrier pattern between the free pattern and the reference pattern; and

a surface local region partially in one surface of the free pattern and comprising a material different from the free pattern.

2. The magnetic memory device ofclaim 1, wherein the surface local region comprises an oxide formed by oxidizing a portion of the one surface of the free pattern or a nitride formed by nitrifying a portion of the one side of the free pattern.

3. The magnetic memory device ofclaim 1, wherein the free pattern comprises a first surface adjacent to the tunnel barrier pattern and a second surface opposite to the first surface; and

the surface local region is partially in the second surface of the free pattern.

4. The magnetic memory device ofclaim 3, further comprising a thin pattern on the second surface of the free pattern.

5. The magnetic memory device ofclaim 4, wherein the thin pattern comprises a first portion having a first thickness and a second portion having a thinner second thickness than the first thickness; and

the surface local region is directly below the second portion.

6. The magnetic memory device ofclaim 4, wherein the thin pattern comprises a first portion of an amorphous state and a second portion of a crystalline state; and

the surface local region is directly below the second portion of the thin pattern.

7. The magnetic memory device ofclaim 4, wherein the reference pattern, the tunnel barrier pattern, and the free pattern correspond to a first reference pattern, a first tunnel barrier pattern, and a first free pattern, respectively, and

further comprising:

a second free pattern comprising a first surface and a second surface opposite to each other;

a second reference pattern on the first surface of the second free pattern; and

a second tunnel barrier pattern between the first surface of the second free pattern and the second reference pattern,

wherein the thin pattern is between the second surface of the first free pattern and the second surface of the second free pattern.

8. The magnetic memory device ofclaim 1, further comprising particles within the free pattern, wherein the particles comprise a material different from the free pattern.

9. The magnetic memory device ofclaim 1, wherein the reference pattern comprises a first magnetic material;

the free pattern comprises a second magnetic material;

each of the first and second magnetic materials comprises iron (Fe); and

a content ratio of iron (Fe) in the second magnetic material is equal to or greater than a content ratio of iron (Fe) in the first magnetic material.

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